Also check out Hoo Haa! (hoohaa.co.nz) with the exact same concept. And then you also have Geldfunk (http://www.geldfunk.de/) in Germany.

With these companies, the advertisers messages are being ‘targeted’ by only being sent to a set demographic group that they want to reach, who have expressed an interest in this product line. But once again, can advertising really attract “true” buyers by paying them to see their advert? You would think that the ones wanting the free advert don’t have the actual money to buy the sponsored product??? In addition, if I was hard-up for cash, what is to prevent me during registration from clicking every category, interested or not, just so I can receive more adverts and make more money?

As for Blyk, very targeted, and for the most part, you get an SMS/MMS and have the option of clicking on a link to see more. You only click if you want to see more. And I hear people are clicking at a pretty good rate. However, we have not seen enough numbers on Blyk just yet. We only know the company is being run by some incredibly smart folks with extensive backgrounds in mobile and marketing.