As a Steam user, I like this idea a lot!

I'm not sure how usertags would be implemented with a scheme like that, though - surely you'd have to supply the Steam user's ID number, rather than their username, for us to be able to build the appropriate URL? And it seems like that's not something that you'd necessarily know; maybe for yourself, but much less likely for someone else.

I may be not seeing something very obvious here but it seems like usertags might be tricky on this one.