Dan Farber suggests that Twitter should just charge a subscription fee as a business model.
"Much of what gets sent via Twitter is a form of self-advertising. If you like Twitter so much, how about paying $5 a month for the privilege."
I think Dan's got it partially right. Clearly there are people who use Twitter as self advertising. The presidential campaigns, Gary Vee, Jason Calacanis... with thousands of followers, many of whom are also influentials themselves with hundreds of thousands, if not millions, of blog and social network eyeballs as a group, are clearly getting a lot more tangible value out of Twitter than someone who uses it to share with 6 friends. I think it's important to have both sets of users.
The casual users with small networks of friends potentially contribute much more to Twitter, in aggregate, then they get back--so charging them the same fee that Jason Calacanis has to be doesn't make a lot of sense, and would put up an artificially high barrier to growth. These users contribute a lot of good data--zietgiest data, brand information, or simply good local content that others might be able to leverage off of to create value themselves. They're not pitching a candidate, product or book, so why charge them?
I think there should be tiered pricing. What do you think Gary Vee would pay for Twitter if, like Dan suggests, it came with some SLA's and rebates for outages...or rather, what is Twitter worth to Gary? Given his recent book sales, I'd say that he wouldn't blink at $50/month--or at least he shouldn't. Neither should Jason, or Obama, CNN, or Zappos. If you have 5000 followers, that's about a $10/CPM to your message across. Given the number of Tweets to phones, the engagement level of the users, I'd say that's pretty cheap, actually. Then we could scale it all the way down to like 300 followers or something at a few bucks a month.