What sort of porn-niche you're in? You can try to make place more targeted ads on page, but still variety of ads is poor. So if your site is about midgets with small tits and ads display fat grannies you will not get much clicks (I get around 1000 clicks every 100000 impressions - because ads are way off target). Also, my ads display white women etc but majority of traffic comes form countries like Sri Lanka, Pakistan, India. I know they watch videos with Asian women on them, but there are no ads for Asians on BLA (no sure anyway). Not sure also what really Asians like - maybe other cultures like different staff? Check also bounce rate, see what your traffic is coming from. If SERPS - check what keywords they've been searching for. Anyway it looks to me to earn descent money from things like BLA you will have to get XXXXXX clicks. So 100000 of impressions is really nothing.
Also, maybe you suck on ads placement? Try to put some of just under "related videos" section - some ads have even style of video thumbnails. Test different site areas. If you see that you have good traffic but not many uniques, try to change position of ads from time to time. After some time visitors become ad-blind and clicks amount drop.
Ignore anything I wrote - I've been unsuccessful with BLA. There was a great thread about adult industry in Noobs section and how to be successful in it.