Nothing's wrong with it - I just didn't feel like installing the Cpanel it requires. As far as differences look at the features between the two and you'll see whether it's worthwhile for you to purchase or not
Why would you want a bunch of surfers blogging ? Well you insert your ad on all their blogs just like free hosts have done since the dawn of the net.. It's $60.00 guys, lol ... Not $6,000 ;)
Or you could build it up and sell to blogger.com etc... as a buyout if you wanted to go that route. Or you could do it for fun for your surfers, hell there's a million reasons