I don't have any big sites but I have a good suggestion for you.
there is no any bigger site than bitcointalk.org to advertise your crypto related site.
Every week the forum Admin Auction forum's ads spot in the auction section..
here is the link:
https://bitcointalk.org/index.php?topic=1608845.0Go there and participate in auction..
the other way is to open a signature campaign.. if you need lots of visitors then do these things..
you can buy ads in other crypto sites. but the result from here ads will be perfect.