SPECIFICATION TITLE OF THE INVENTION INFORMATION DISTRIBUTION DEVICE, INFORMATION RECEPTION DEVICE, SYSTEM, PROGRAM, AND METHOD Technical field The invention relates to an information distribution device, an information reception device, a system, a program, and a method. Background art An advertisement is one of important ways for well informing clients of commodities and services, and it is preferable to distribute a highly-effective advertisement. For example, Patent document 1 describes one example of an image display system that changes advertisement displays depending on client features. [Related art document] [Patent document] [Patent document 1] Japanese Patent Application Laid-Open No. 2004-157498 Summary of the invention Problem to be solved by the invention The system distributes an advertisement to people in front of an image display device in a public space. The system occasionally distributes the advertisement to a person who has no interest in content distributed from the image display device (e.g. a person who passes fast). Therefore, advertising effect cannot be fully increased. A TV commercial is well-known as an advertisement which impresses a large indefinite number of clients on commodities. An advertisement corresponding to clients' tastes cannot be distributed using only such push advertisement. The push advertisement does not passively generate full advertising effect. In order to solve the above problem, an object of the invention is to provide an information distribution device, a system, a program, and a method which can increase advertising effect by distributing an advertisement which matches a person who is expected to be affected by appeal effect. Means to solve the problem In order to achieve the object, one aspect of the present invention includes an information distribution device that obtains content from content storage means, transmits the content to a terminal device having display means for displaying an image of the content, receives a personal attribute from attribute collection means, included in each of the k (where k is a natural number which is two or more) terminal devices, the attribute collection means for collecting the personal attribute on a person in a viewable region for the image, selects advertisement data from an advertisement storage unit based on a result of statistical processing on the personal attribute collected while transmitting the content, and transmits the selected advertisement data to the n (where n is a natural number greater than k) terminal devices. The present invention provides an information distribution program, causing a computer to execute a step of obtaining content from content storage means, a step of transmitting the content to a terminal device having display means for displaying an image of the content, a step of receiving a personal attribute from attribute collection means, included in each of the k (where k is a natural number which is two or more) terminal devices, for collecting the personal attribute on a person in a viewable region for the image, a step of selecting advertisement data in an advertisement storage unit based on a result of statistical processing on the personal attribute collected while transmitting the content, and a step of transmitting the selected advertisement data to the n (where n is a natural number greater than k) terminal devices. The present invention provides an information distribution method, comprising: obtaining content from content storage means; transmitting the content to a terminal device having display means for displaying an image of the content; receiving a personal attribute from attribute collection means, included in each of the k (where k is a natural number which is two or more) terminal devices, for collecting the personal attribute on a person in a viewable region for the image; selecting advertisement data from an advertisement storage unit based on a result of statistical processing on the personal attribute collected while transmitting the content; and transmitting the selected advertisement data to the n (where n is a natural number greater than k) terminal devices. The present invention provides an information distribution device, comprising: advertisement storage means for storing advertisement data and an advertisement attribute associated with each other; conversion-information storage means for storing a first conversion rule from a personal attribute to the advertisement attribute; and information distribution means for obtaining content from content storage means, transmitting the content to display means for displaying an image of the content, receiving, from attribute collection means for collecting a personal attribute on a person in a viewable region for the image, the personal attribute, determining the advertisement attribute based on the personal attribute, collected while transmitting the content, and the first conversion rule, selecting the advertisement data related to the determined advertisement attribute from the advertisement storage means; and transmitting the selected advertisement data to the display means. The present invention provides an information distribution program, causing a computer to execute, a step of obtaining content from content storage means, and an information distribution step of transmitting the content to display means for displaying an image of the content, receiving a personal attribute from attribute collection means for collecting the personal attribute on a person in a viewable region for the image, receiving the personal attribute collected while transmitting the content, determining an advertisement attribute based on a first conversion rule, being stored in conversion-information storage means, from the personal attribute to the advertisement attribute, and transmitting the selected advertisement data to the display means. The present invention provides an information distribution method, comprising: obtaining content from content storage means; transmitting the content to display means for displaying an image of the content; receiving a personal attribute from attribute collection means for collecting the personal attribute on a person in a viewable region for the image; receiving the personal attribute collected while transmitting the content, and determining the advertisement attribute based on a first conversion rule, being stored in conversion-information storage means, from the personal attribute to the advertisement attribute; selecting advertisement data associated with the determined advertisement attribute from the advertisement storage means for storing the advertisement data and the advertisement attribute associated with each other; and transmitting the selected advertisement data to the display means. The present invention provides an information reception device, comprising: attribute collection means for collecting a personal attribute on a person in a region where an image of content displayed on a display for displaying the content and advertisement data is viewable, where the content and the advertisement data is received from an information distribution device including advertisement storage means for storing the advertisement data and an advertisement attribute associated with each other, conversion-information storage means for storing a conversion rule to convert the personal attribute to the advertisement attribute, and information distribution means for selecting, from the advertisement storage means, the advertisement data associated with the advertisement attribute determined based on the personal attribute, collected while transmitting the content, and the conversion rule, and transmitting the selected advertisement data, and for transmitting the personal attribute to the information distribution device. The present invention provides an information reception program, causing a computer to execute a display step of receiving and displaying content and advertisement data from an information distribution device including advertisement storage means for storing the advertisement data and an advertisement attribute associated with each other, conversion-information storage means for storing a conversion rule to convert a personal attribute to the advertisement attribute, and information distribution means for selecting, from the advertisement storage means, the advertisement data associated with the advertisement attribute determined based on the personal attribute, collected while transmitting the content, and the conversion rule, and transmitting the selected advertisement data, and an attribute collection step of collecting the personal attribute on a person in a region where an image of the displayed content is viewable and transmitting the personal attribute to the information distribution device. The present invention provides an information reception method, comprising: receiving and displaying content and advertisement data from an information distribution device including advertisement storage means for storing the advertisement data and an advertisement attribute associated with each other, conversion-information storage means for storing a conversion rule to convert a personal attribute to the advertisement attribute, and information distribution means for selecting, from the advertisement storage means, the advertisement data associated with the advertisement attribute determined based on the personal attribute, collected while transmitting the content, and the conversion rule, and transmitting the selected advertisement data; collecting the personal attribute on a person in a region where an image of the displayed content is viewable; and transmitting to the information distribution device. Effect of the invention The present invention provides an information distribution device, a system, a program, and a method which enables to increase advertising effect by distributing an advertisement which matches a person who is expected to be affected by an appeal effect. Brief explanation on drawings [Fig. 1] Fig. 1 is a block diagram illustrating an example of a configuration of the first exemplary embodiment, [Fig. 2] Fig. 2 is a diagram illustrating an example of an advertisement storage unit 11 of the first exemplary embodiment, [Fig. 3] Fig. 3 is a diagram illustrating an example of a content storage unit 12 of the first exemplary embodiment, [Fig.4] Fig. 4 is a flow diagram illustrating an example of an operation of the first exemplary embodiment, [Fig. 5] Fig. 5 is a diagram illustrating an example of a conversion-information storage unit 13 of the first exemplary embodiment, [Fig.6] Fig. 6 is a diagram illustrating an example of a schedule table of the first exemplary embodiment, [Fig.7] Fig. 7 is a diagram illustrating an example of a coefficient table of the first exemplary embodiment, [Fig.8] Fig. 8 is a diagram illustrating an example of a conversion-information storage unit 13 of the second exemplary embodiment, [Fig.9] Fig. 9 is a flow diagram illustrating an example of an operation of the second exemplary embodiment, [Fig. 10] Fig. 10 is a diagram illustrating an example of a content storage unit 12 of the third exemplary embodiment, [Fig. 11] Fig. 11 is a flow diagram illustrating an example of an operation of the third exemplary embodiment, [Fig. 12] Fig. 12 is a block diagram illustrating an example of an information distribution device 1 of the fourth exemplary embodiment, [Fig. 13] Fig. 13 is a block diagram illustrating an example of a configuration of a terminal device 2 of the fifth exemplary embodiment, [Fig. 14] Fig. 14 is an explanatory diagram of an example of a display unit 20. Exemplary Embodiments to carry out the invention Exemplary embodiments to carry out the invention are explained below with drawings. In all the drawings, the same elements have the same reference numerals and explanations thereabout are optionally omitted. Each unit which configures a device of each exemplary embodiment is configured by hardware, e.g. a logic circuit. Each unit may include a control unit, memory, a program which is loaded on the memory, a storage unit, like a hard disk storing the program, and an interface to connect a network. Each unit may be a combination of hardware and software. Unless otherwise noted, an achieving method and a device thereof are not limited. The control unit includes a CPU (Central Processing Unit), or the like. The control unit operates an operating system and controls all of the devices, reads programs and data from a recording medium placed in a drive device to the memory, and executes various processes according thereto. The recording medium may be an optical disc, a flexible disc, magneto-optical disc, an external hard disk, a semiconductor memory, or the like. The recording medium records a computer program in a computer-readable manner. The computer program may be downloaded from an external computer (not shown) connected to a communication network. The communication network may be Internet, LAN (Local Area Network), a wireless communication network, or a network configured by a combination thereof.