Initially, I think it's too much effort to develop your
own software platform.
But you can use some ready software like Yahoo Messenger.
No cost at all. In the longer run, the cost will be marketing.
I think it's very hard to find partner online. Even if you do
find one, it's hard to work out on the longer run. So better
fucus on the friends you know already or other people
have good words. (Even that could be an issue.)
