> I think a more interesting argument would be to say, the free plan has facebook, and facebook subsidizes your internet (something AT&T is already doing with ads), and the median plan has twitter, and you can only use VPN to connect to your office on the highest plan, even if you use almost no bandwidth.

Here's the problem. Any such regime will be structured with incumbent use cases in mind. What if a new VPN-like protocol emerges that can be used to ensure more privacy (e.g. TOR). Now only those who can afford the highest tiers of service will be able to access it. Basically the internet rich get richer because they have access to technology that a family subscribing to mid-tier do not.

The other problem is that ISPs are not interested in the cutting edge of the internet. If this was 2005, your plan would have the mid-tier selling us MySpace access and Facebook would only be on whatever tier above that gives "neutral" web access - how does that not skew the market forces that pushed Facebook to the top of the heap and why should an ISP be allowed to skew them in this way?