I looked at leaserig.net
Seems like it's an easy way to lose btc. I suppose if you mined a coin with PoS interest like HBN, you could in the long run recoup that lost btc.

How are you figuring a profit from them? By speculating new coin mining turns into value later?

I'm about to buy a Gridseed blade to replace my GPU farm. Seems like a decent site to sell my hashpower and make more than if I were hashing myself.