Heres a few Q&A's for you, hopefully this will help you:
Questions & Answers:
Q: Do I earn $6 for 60 posts, $9 for 90 posts, etc?
A: No. You earn $3 if you make AT LEAST 30 contributory posts in a calendar month. If you exceed 30, there are no additional bonuses.
Q: Does this bonus count toward the $15 minimum cashout amount?
A: This bonus counts towards the $25 cashout minimum, but since it's a bonus, it does not count towards the $15 in offers completed cashout minimum. It's just like a referral bonus, or any other bonus.