Twitter founder Biz Stone has confirmed that the network might take advertising at some stage. More specifically he's refused to say it won't. The company has just revised its terms and conditions and as part of the overhaul Mr. Stone has said on a blog that he's keeping the door open to advertising. So he's not saying no, he's not saying yes.

This is an entirely sensible view to take since neither he nor anyone else can predict the direction a company will take at only two years old. Markets change, conditions change so of course he's keeping an open mind.

The Twitter community doesn't seem all that pleased.

This is going to be a bigger issue. Twitter and the rest of the social networking world has built itself a substantial problem. Everyone, by now, expects these things to be available without charge and mostly advert free. And I'm here to tell you, people, it isn't going to happen. Initial investments in these various start-ups were made way before the financial climate turned septic but even then it's massively unlikely that these businesses were set up without any thought of ever turning into profit.

It's going to look odd, in history, when we turn around and reflect that in a few very short years we all had free Facebook, Twitter, Myspace, YouTube, mail from Google and goodness knows what else. It's going to look even odder that we took it for granted. Sometime over the next few years we're going to have to decide in what way it's going to be acceptable to pay for it all; it'll be interesting to watch the resistant users in these communities as the financial realities start to bite.