Hi krishatnet,
thank you for an interest.

Both Bee-ads.com and Bitsense-ads.com accept all niche websites.
With Bee-ads.com there is the eCPM decided by advertisers bids.
With Bitsense-ads.com the floor eCPM is $0.29. Average eCPM for 12 websites we are testing our adserver with is $0.83 but there are obviously plenty of factors involved for every specific page so it could go way up or way down. But the floor is set up and should be kept - the fill rate with it is 87%, the rest we cover with passback tags (re-targeting).