[hkarthik]

I could see these sites working out if you have a decent amount of cofounder material in your local city. In my city there are very few so finding a good cofounder is a much more difficult prospect.

I have heard mixed things about those trying to work with a cofounder remotely. Generally that only works if you have a previous working relationship. Such relationships are hard to establish remotely while also pursuing a new, risky venture.