for better attraction he should go with monthly payment with minimum posts
I agree. I actually have no idea how many posts are expected. I'm just going to post like usual (some days more active then others) and see what happens next week.
If it wasn't specified, then there is no post requirement.
The campaign was badly organised. Half of the participants are using incorrect links. Payments made in advance + no requirements mean that people could just take money and jump to another campaign.
Project itself is not doing great, most of free ad space is still unclaimed, so don't think anyone would pay for that.
Interesting idea - poor execution.