Ask HN: Any good BuySellAds(BSA) alternatives?

We are PSD to HTML/WP agency in Sydney, Australia and the business is pretty stable. http://www.xtmlweaver.com We've been using BSA for awhile and the monthly budget is about $2K for advertisings (cross few different sites). I'd say that BSA is pretty good and hassle free service. But in recent month the CTR has been dropped for us so the money we spent doesn't give us good return. I am wondering that are there any good BuySellAds(BSA) alternatives for tPSD to HTML/WP type business? I don't think there is any wrong about BSA and actually I still really like their service, just want to see the potential for others. Cheers,