Weird business model?

Image via CrunchBase, source unknown I haven't used Ning, but I was checking it out. It seems they have a weird business model. It's free for you to use, but if you want more control over what shows, you have to pay. You want to control the ads? That'll be $19.95 /month. Want to use your own domain name? $4.95 /month. Remove promotional links that are added by Ning? That'll cost you $7.95 /month.

I know you can get HBO for a subscription price, and skip the ads, but I wonder if other businesses could work that way. Want to shop for groceries, but only want to see the products you'll buy? That's $19.95 /month...