There's also been a lot of talk about how this monetization might affect the fundamentals of the service. The thoughts are that Twitter's usage plan for the service might be quite different to how users are currently using it. Twitter have not been afraid to tinker with the raw operational mechanics either (I.e the recent follow/DM debacle).

 So, people are quite anxious about how Twitter might change and adversely affect their service. I say, don't be - because if Twitter change the game too much it just opens the door to someone else to fill the void. "But!" (I hear you shriek) "Twitter have 500 jazillion users - that's end of game!". To which I would say the following:

 1) User bases online are very, very fickle - they can blow away in the breeze - this months exponential growth rate could be next months unprecidented stagnantion rate.

 2) Those who live by the API can die by the API. Twitter is a very simple service which is also the reason for it's success. Many 3rd parties have greatly enhanced the service by building on the application programming interface (API). This same API which has helped fuel Twitter can also be the key to it's undoing - eg Google (for example) could use this API to tap in all your profile information/tweet history/followers etc and dump you into a new service. You are not forever tied to Twitter. If want to provide a service which is open (as any good web app should be) this is a necessary evil - you can't have your cake and eat it.

 3) This life streaming/micro blogging concept is new terroritory. Yes Twitter are at the healm in these uncharted waters but that also means they could be the first to hit the iceberg. History tells us that the early race leaders aren't always the "winners".

 Why do I mention Google as a possible competitor? Well, they're the obvious one. They know how to host massive applications which require equally demanding uptimes. They are also very, VERY interested in what we have to see and being able to search/index those tweets.

 So, Twitter are massive - will they be the big player in 3 years time? We'll see but it's not set in stone.