providing an online computer database featuring real estate sales lead information; provision of space on web sites for advertising the goods and services of real estate professionals for the purpose of attracting real estate leads and gathering information about said leads; dissemination of advertising on a global computer web site for identifying and referral of real estate leads and providing information on said leads; providing marketing information, real estate lead generation management information, and customer acquisition information to real estate professionals via the Internet; advertising services; marketing services