If Facebook is really the next marketing platform, the guys at Loladex will have guessed right. The new rating and review company, formed by two alumni of AOL Search and Yellow Pages, had initially been incubated as a destination site that enables user reviews, business listings and third-party content from sites such as OpenTable.com and ServiceMagic.com. Sometime last year, the decision was made to build specifically for Facebook.

The key advantage of the Facebook-only strategy? Leveraging Facebook’s discrete social and geographic groups, and growing user base. It is something that destination sites such as Yelp, Kudzu, Citysearch, YellowBot and Boorah don’t easily do. When was the last time you looked at a review and wondered whether the reviewer had similar tastes? The idea here is to stick with established friends.

But there are risks. Facebook could compete directly against the site, marginalizing Loladex as a little used “application” (like six other applications I have that are already shunted to a side menu). Or maybe Facebook never really becomes a universal platform, and users find themselves shut out of the larger universe.

That seems possible. Facebook may be a little stratified between the college/post-college crowd, and an older professional set. There is little in-between. And the professional group of friends on Facebook may not have common tastes in restaurants (or gyms).

But Loladex founder Laurence Hooper is gungho on the Facebook tie — which is one-way. The company doesn’t actually work with Facebook. “Some people believe it is on the verge of being abandoned, but I believe the opposite,” he says. “Facebook has enormous potential, and the serious applications are just starting to arrive. Products like Loladex will help people realize that Facebook is useful, rather than just entertaining.”

In any case, it isn’t really about Facebook. In July, the site will launch a broader site based on the new “open social” standard that Yahoo!, Google and others are participating in. What Hooper and fellow AOL YP alum Dan Goodman are looking at is a social network that is “fully portable” and “scales easily. Don’t ask people to do the work” of exporting their friends — and their friends’ content — from one network to another, he says.