If you look at who that account is following, there seems to be a whole network of people using accounts with names close to (or impersonating) celebrities who all re-tweet each other and promise "10 follow-backs for each follow" and "if you follow <random> I'll follow you" etc.
Looks like either some kind of weird social hack/club or I don't know what..
This account has close to 1M followers, and appears to be in that same network or loop of spammy follower-harvesting group..