Portals are the latest revenue-generating scheme to sweep the Internet.
The theory is that if you attract enough visitors by making your Web site a gateway to the untamed and uncharted Internet, advertisers will write large checks in your company's name. Netcenter tends to draw a more corporate and techno-savvy crowd. The AOL and Netcenter portals rank among the most-visited sites on the Web. They threaten to dwarf competitors, most of which must adopt a niche strategy or perish. Let's say you're a sales exec headed for a big meeting and you need travel info.