Difficult one – yes, the company has to make money to survive, and ads/subscription appear to be the only options.

And, I’ve just discovered that they’ve stopped making it easy to get an RSS feed from a particular user without recourse to code/3rd party apps. ( http://support.twitter.com/groups/31-twitter-basics/topics/111-features/articles/15361-how-to-find-your-rss-feed ) As others have said, payment will inevitably change Twitter – and many users don’t have the technical skills required (or the inclination to learn them) to really consider the alternatives; until those have sufficient mass … then they’ll change models.

Me, personally, I just don’t know. I do find it incredibly useful – but would I be willing to pay. Probably. But, it would depend on the amount. Would I be willing to put up with (aka ignore) ads; more likely.