By the 1990s, sophisticated electronic marketing will have replaced traditional and increasingly expensive door-to-door selling. Computerized top-down selling will enable prospects to be categorized according to potential payback. An electronic database created for target areas can be stratified, continually updated, and used along with dialogue assists and automatic dialers to call a test sample of a customer base. Sales calls can be made by using computers to determine factors needed to match products with buyers and to then pose the factors as questions asked of prospects. Direct mailings can be selected using software programs to review data resulting from the calls and can be followed by a 2nd phone call. Electronic marketing also can provide live presentations, follow-up data, letters, and proposals, and can enable buyers and sellers to negotiate through live teleconferences.