Obviously massive sites like facebook are very ajax heavy to the point of being unusable without it, but for average joe website should i be looking to roll out ajax interaction where i would previously use standard form posts.
I've added ajax to a couple of my admin areas and one "closed" web based application so far. On the "closed" app, one of the 50 day-to-day users had to be upgraded as he was using an early explorer 5.
what percentage of internet users can use ajax (for any reason, not just browser age)?
Is it worth ignoring the percentage of users that can't use ajax in favour of better interaction (and in many cases, easier, quicker development.)?