FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFfCATfON [See section 10, Rule 13] SYSTEMS AND METHODS FOR APPENDING CONTENT TO MOBILE MESSAGES; COMVERSE, LTD., A CORPORATION ORGANIZED AND EXISTING UNDER THE LAWS OF ISRAEL, WHOSE ADDRESS IS 29 HABAR2EL STREET, 69710 TEL AVIV, ISRAEL. THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED. Background of the Invention Field of the Invention The present invention relates to a system and method for appending content to mobile messages, and more specifically to appending a context-based sponsorship message to a text or multimedia message, Background of the Invention Advertisers are constantly searching for additional ways to present an advertisement to a user. The Internet has proved a significant tool for advertisers looking to present a message to a target audience. Sponsored services on the Internet are an established industry that is looking to expand. Internet leaders are seeking ways to leverage on their market position into new domains. The mobile domain is considered by many to be the biggest potential and the next logical step. The mobile advertisement market is beginning to change. Content developers are training their sights on cell phones, which they see as the launch pad for applications targeted at personalized mobile services. New services bring up a whole new set of billing challenges. Advertisement-based revenue provides an opportunity for service providers to put a focus on the end users by providing free services. Mobile messaging is an integral part of the mobile industry and contributes significantly to the total mobile service revenues of almost every network operator on the planet. During the period 2006-2012, the worldwide mobile subscriber base is expected to increase from 2.65 billion to 4.81 billion. Short Message Service ("SMS"), launched in 1992 in Europe, has proven to be the industry's greatest non-voice success story and by far the most successful data application. Although revenues from voice calls still comprise 80 percent of total mobile service revenues, operators globally are focusing on data services for increasing their average revenue per user ("ARPU"). Of the various data services (such as mobile messaging, mobile gaming, browsing, etc.), mobile messaging has been the frontrunner, with SMS leading the way. Multimedia Messaging Service ("MMS") has also started experiencing more significant growth in various regions, especially in North America. Therefore, what is desired is a system and method for advertising in the mobile messaging medium that is easy to implement, does not comprotnise existing messaging features, and provides relevant advertising content to a subscriber. Summary of the Invention The present invention relates to a system and method for appending mobile messages with a sponsorship message. The sponsorship message can be appended to any type of mobile message, whether Short Message Service ("SMS"). Multimedia Messaging Service ("MMS"). Instant Messaging ("IM"), E-mail or next generation Mobile Messaging. In one aspect, the characteristic of the message or the subscriber sending or receiving the message. The present invention also relates to a system for appen