Says the phone numbers are free for personal use. What's the point? You don't have the phone associated with the number so can't make or receive calls. Is there some scam here I can't figure out?
Click on the number and it supposedly shows SMS's that have been sent to it. You would use it when you don't want to give out your real number for a verification step if you didn't want to.
Craigslist offers a similar service, called Craig’s Number. Been around a very long time; I’ve used it occasionally to sell and I wasn’t the victim of any sort of scam. You can even choose the duration that the phone number works for.