hi, all banner spaces are on bid system... it means you can make offer to 300x250, 728x90 and 468x60 banners
minimum is 100k satoshi / space / 30 days,  but now you can get it for 60 days (extra 30).

for example if you bidding 200k satoshis, there is double chance for displaying your ad.
i am sending to advertisers tracking links, where you can check your stats

there are reflinks allowed too,but limitation = crypto related pages