There's a reason that the majority of MFA sites do not convert. When executed properly, MFA sites can actually be just as converting as a user directly from the Google, MSN, or alike search network.
The fact of the matter is that the majority of MFA site owners made sites that displayed ads based on very high paying keywords. For instance, "car insurance".
Then these same people decided to go to Google Adwords and bid on keywords that were 10x or less expensive such as "cars" or even worse - "computers", which had really nothing to do with car insurance. Their hopes were that they'd pay $0.05 per click for low paying keywords, and they'd need at least 1 out of 100 of these to click a $5 ad in order to break even.
Well they definitely accomplished their mission. A 1% CTR is not hard to get even on completely unrelated set of ads. If they were to get 2 clicks out of 100, they'd in theory double their revenue (based on this example).
MFA (or better known as Arbitrage) can be very conferting if done properly. Buying visitors for "free games" for $0.10 a click and redirecting to a page that displays ads for "free video games" at $0.50 a click can make you money and still keep the conversions high since the user is looking for the same relevant topic.
Big "MFA" companies still exist: ToSeekA.org, FindStuff.com, Shopica.com, etc. The reason is because they have millions of keyword data and know which keywords to bid on and which ads to display to show ads based on same relevant topic.
So at the end of the day, there are only 2 ways to be in the "MFA" game and still send out converting traffic to advertisers.
1) You bid on the same keywords and display ads for the same keywords.
2) You bid on different keywords that are within the same topic - but to do this you must have a lot of data and a lot of time to pick out the right keywords.