I think that's ridiculous. Half our link sales are going to a company just for selling the links. I mean, why would anyone want to cut their monthly revenue in half to pay a company, when you could just get links on your own. Don't make no sense to me.
Because they have done following Created a market place for you to sell your link - promote that market actively. So you don't have to scout for individual link buyers. Run and Maintain the system so you don't have to worry about adding/removing links, reminding the link buyer to pay up at the end of each month (or remove his/her link manually from your site)
You can have both of them together - TLA is different than adsense. TLA Payoff depends on worth of link on your site (and demand in your niche).
If someone buys your links TLA pays quite well (by DP standards) - about $6 or $7 per month per link on a PR3 site would be normal. Getting accepted isn't that easy - the bare miniumum are an established site, Alexa < 1 million and PR3. Even if accepted there's no guarantee people will buy your ads. I currently have 3/24 ad slots taken.
Actually they pay quite better .. I'm really happy with TLA... depends on the traffic .. if you got high traffic you get good money ... Cheers, Venetsian.