I was able to sell some ads before. But not now. It's weird. My site is an adult site with alexa rank:2,900. The cost is only $20/wk. Nobody buy ads from my site.
more info please!? Generally I would lower the price and the number in the ads-pool (more clicks/ad), to attract more buyers. And higher the price again when some slots are already sold. Also keep the ads/pool always as low as possible: Example: If 6 ads are sold, make it 7 ads in the pool. If 7 ads are sold, make it 8 ads in the pool. ps.: You have to experiment a lot with adengage, to find out what works for your site.