Meh, the problem and it's solution isn't that original so I wouldn't scream ripoff just yet. Also The other site want's you to install an extension. In my personal experience (a while back so don't know current situation) it was a bit buggy, and the offline reading thing didn't work very well. With this you can have sort of the same (minus offline reading). I still prefer delicious (tag: toread or towatch) though, have to admit I'm a bit of a fan of the delicious site, so I'm not that objective.

Edit: How do you plan to monetize this service? Or is this more for fun?

There really aren't any plans to monetize it. If it manages to cover it's own costs via donations or possibly ad sense, then I'd be happy.