iMore:

Literally every time I work in the computer store, we’ll get a customer whose Mac is plagued with problems they don’t understand: Their Mac is acting slow. It crashes. And more. And in more cases than not, we find that they’ve installed a program called MacKeeper. Removing MacKeeper fixes the problem. So what is MacKeeper and why should you avoid it? Read on for details

It’s definitely “crapware” and the company’s tactics are sleazy. As Peter says, avoid and warn others.