I'm REALLY new to Steemit. So can someone please explain what's happening here?

https://steemit.com/sbd/@checkthisout/sbd-correction

And it continues, earning large chunks on comments...

And then @checkthisout goes on to win awards...

Clearly this is some kind exploitation.

Now, take a look @grumpycat 's wallet: https://steemit.com/@grumpycat/transfers

How does a Steemit account have a value of $2,903,761.90 after only join this past November?

Now scroll down and look at the bottom of transfer history:

Receive 211980.000 STEEM from @checkthisout

Needless to say, I'm a bit of confused. I skimmed through some of the comments of that post and it looks like it was some kind of exploitation in Steemit being abused.

Anyone have insight?