> but with service only capable of around 100mbit at the highest.
I can tell you from my direct personal knowledge, that my neighbors' and my combined speed through this ISP can exceed 200mbit, and there is another ISP available in this building that can exceed 110mbit. We are getting a third ISP in 2014 that is several orders of magnitude faster, so that will be at least 3 lines to this 10-unit building that have objectively-measured speeds exceeding 100mbit.
It is entirely possible that this 200mbit+ backhaul is shared over multiple buildings, but if that is the case, I do not notice. I move on the order of 25GB a day, 7 days a week, 365 days a year, and consulting 2 years of router logs suggests that I have never dropped below 30mbit (e.g., assuming both endpoints are up). That is sufficiently close to the performance of a dedicated line that moving any closer is irrelevant for any application I would ever have.
What I am saying is that this shared line is managed very well. And it is reasonable expectation for a user of a shared line that it is managed well. It is a reasonable expectation that the user achieve advertised speeds most of the time, and if this is unachievable, then the ISP should advertise achievable speeds. My ISP is perfectly capable of advertising 200mbit (since it is objectively achievable) but instead they advertise 35mbit. It is true that they do not always achieve 35mbit, but the performance is sufficiently close.
For example, it is at this very moment a peak time for a residential area. A speed test suggests I can achieve 33mbit down (94% advertised speed) and 5.5 mbit up (110% advertised speed). This is well within the margin of "close enough" for people who aren't doing high-frequency trading.
> So you won't get every house in a residential area.
Neither will you get every business in a business area. You have not presented a basis upon which to believe that it is more likely for an ISP in a competitive market to get a business customer than a residential customer. So if we assume the fill rate for a residence is 50%, we should assume a similar fill rate for businesses, and the geometric argument I presented still holds.
> If you don't understand the agreement you signed, call your cable company.
It's not a matter of me "not understanding" the agreement. It's a matter of it being objectively unclear.
The cable company is not the arbiter of what the agreement I signed means. The meaning of the agreement is objectively determined by either a judge or the AAA, the application of contract law in the State of Texas, and a good dictionary. Based on my knowledge of the forgoing, I believe that I could host an extremely high-traffic personal website within the terms of the agreement.
Would they like it? No. Will they threaten to cut me off as a customer? Possibly. Is it a violation of the agreement I signed? No. So here we have a situation where the real rules of the road (e.g., they will stop serving me as a customer if I do this) are not in fact the agreement I signed when I signed up for the service, but are arbitrary and unwritten decisions that are subject to the whim of some person at the ISP. I am saying that your claim that most ISPs have clear and fair written rules is objectively false, because there is no rule in my agreement that prevents me from saturating my connection all the time, and yet there are unwritten rules that prevent me from doing so.