BSave.io

BSAVE.IO How it works from http://bsave.refr.cc/tristanj on Vimeo.

As they explain in the video, one cool thing about BSave is you get returns daily. I deposited my investment yesterday, and already today have a small amount of bitcoin I could withdraw.

Noticeable drawbacks

High withdraw limit. My withdraw must be greater than 0.01 BTC.

Of the three services I have invested with (BSave.io, Magnr.com, and Bitbond) http://bsave.refr.cc/tristanj looks to be the most promising.