So you are paying 0.08BTC per month no matter how many posts made/a certain amount?
I suggest changing to a capped, pay per post system so you get more for your money OP...anyone can sit back and do nothing on this sort of deal.
This program is great for those not so active people.
For Sr member, 0.08 btc for 50 post = 0.0016 btc per post.
For Full member, it is 0.0008 btc per post.
And don't forget, you can join other paid sig programs along this one, like what BigBoy89 is doing.