What the other guys here said, beef up your advertising. Work on juicy text pitches, be in the surfers face!
As far as traffic/conversions are concerned, 10k hits (uniques) to your freesites pr month really isn't that much. How many sites have you built? How often do you build/submit? You have to give it some time for the "snowball" effect to take place.
That said, if you get 1 sale/week from 10k uniques to your freesites/month, that isn't so bad at all. Assuming an average CTR of 10% you're sending 1,000 uniques to sponsor which would give you a conversion rate of 1:250. Pretty decent.
