Social networks like MySpace and Facebook are among the leaders in user engagement, with many users returning daily and some visiting many times a day. They’ve almost reached the same level of engagement as email* and have double the engagement of news and sports sites. Yet they present a special problem for marketers: the content is so compelling that few people bother to look at the ads.

The ads have been poorly targeted banner ads or Facebook’s “flyers.” The flyers target a specific network, but even those frequently miss the mark. I’m in the Northwestern network and frequently get ads for coffee shops near the campus in Evanston.

The future of marketing on social networks is getting users to create and distribute advertising information for you.

Two of my favorite Facebook apps are MyTech and HotLists.

MyTech is an application from CNet that allows you to publish your technology purchases. Here’s a screenshot from my profile:

My friends can see what I’ve bought and how I’ve rated it. The purchase and review appear on my mini-feed. (Facebook will soon change the rules on its news feed, allowing the review to also get distributed in my friends’ news feeds.) The Facebook platform and MyTech are enabling word of mouth well beyond the people I talk to on a regular basis. The personal connection also allows my friends to get more information on a product by asking someone they know.

Another great application is HotLists from the makers of HotOrNot. The HotLists application allows you to associate yourself with brands. Here is mine:

Who is going to associate themselves with brands?

Lots of people, if you make it easy enough. We do it every day when we wear a Product(RED) T-shirt, drive a BMW or put white earphones in our ears. On Facebook, HotLists’ statistics page shows that more than 38,000 people use the application every day; about 3.8 million have it installed.

A natural extension of the HotLists application is a brand recommendation engine that suggests brands you might be interested in based on the brands you’ve already selected.

This won’t work for all brands. I don’t see people putting Metamucil or Depends on their Facebook profile. But it can work for brands like Keen. Whenever I wear my Keens, it’s a conversation starter with other Keen fans.

My brand attributes also imbue the brands I choose. People who know how much I travel know that Briggs and Riley makes luggage that can travel a million miles.

* This is based on the general U.S. Internet population; in the college audience, social networks have likely exceeded email in engagement.