MacKeeper: Legit?

So you may, or even may not, have heard of a Mac software cleanup/antivirus/antislow program called MacKeeper. It markets itself on Google as:

Ensure your Mac’s top performance with MacKeeper – an award-winning system utility for Mac that offers a completely new approach to system care.

Judging by their advertising, which if you haven’t seen it, is just overly invasive, and presented in such a way that a certain type of tinned meat [[spam]] comes to mind as soon as you see it, you’d think they’re not legit