Following the thread here, I think what you are asking for is unreasonable given the current infrastructure or massively unpopular.
In the current environment what you are asking for is completely possible. Comcast will give you your speeds, but if they see you are seeding your debian torrents for too long, they will throttle your connection. Now they could advertise this, but we know how unpopular connection throttling is. However in a way, a connection throttle is your minimum service guarantee - your speed will never go below the throttle.
Now I don't know anything about laying internet pipe, but lets say we gave everyone minimum service guarantees, how much do you think that would cost, and how much would you be willing to pay for a given speed? It may be completely possible that Comcast is fine with your seeding as long as you limit your speed to percentage of that number.
This doesn't really refute your point, but given these two constraints its easy to see why ISPs may choose to go the "up to XMbps" route rather than the "minimum allowed route." Would it really change anything for you if you found out that your minimum service guarantee was 768kbps at your current price point?
"Now I don't know anything about laying internet pipe, but lets say we gave everyone minimum service guarantees, how much do you think that would cost, and how much would you be willing to pay for a given speed? It may be completely possible that Comcast is fine with your seeding as long as you limit your speed to percentage of that number."
I think the cost of providing such a guarantee depends on the guarantee, and therein lies the problem. Right now, I suspect that a typical cable modem connection would only be able to guarantee dialup speeds, due to how massively oversold the bandwidth is. Of course, most people do not seed torrents or run web servers or whatever else on their home connection, and so we never see service so degraded.
"Would it really change anything for you if you found out that your minimum service guarantee was 768kbps at your current price point?"
Sure: I would have a much higher opinion of my ISP. Frankly, I would have a higher opinion if service classes were based on such minimum service levels rather than maximum levels: I would much rather pay for at least 768kbps than at most 20Mbps, particularly if "at least 768kbps" meant "at least 768kbps, and higher throughput when available."
In the current environment what you are asking for is completely possible. Comcast will give you your speeds, but if they see you are seeding your debian torrents for too long, they will throttle your connection. Now they could advertise this, but we know how unpopular connection throttling is. However in a way, a connection throttle is your minimum service guarantee - your speed will never go below the throttle.
Now I don't know anything about laying internet pipe, but lets say we gave everyone minimum service guarantees, how much do you think that would cost, and how much would you be willing to pay for a given speed? It may be completely possible that Comcast is fine with your seeding as long as you limit your speed to percentage of that number.
This doesn't really refute your point, but given these two constraints its easy to see why ISPs may choose to go the "up to XMbps" route rather than the "minimum allowed route." Would it really change anything for you if you found out that your minimum service guarantee was 768kbps at your current price point?