Just found out about Bitconnect as well which is based on compound interests. That platform is a bit so so and i would not recommend it 100%. You don't even know who is behind the project and there is very little known about it. I did invest a small amount for fun myself.
Steem however have lots and lots of potential. Its a ambitious project and the more people joining this the more power we take back from other social media platforms. I hate the censorship happening everywhere now days. Hopefully this is a more open platform as data is always kept into the chain.

And as a bonus we get this compound interest, that's just an extra incentive for me.