You are all forgetting you are paying for a shared service. This is a common seeing in the UK. "£25 for a totally unlimited 8Mb Max service." They forget to mention on the ads you get throttled as low as 512 speeds or worse depending on ISP and traffic type. Due to the competitive nature of ADSL in Britain there is a price war of who can offer the cheapest service. All claiming unlimited. Some traffic shape worse than others, some actual have a "Fair Usage Cap" on their unlimited.
The best ISP's have no traffic shaping but have a cap in place. The average price is ~£25 for 30GB. My ISP (Entanet) offers 30GB peak and 300GB offpeak, and as expected for a couple of hours when off peak starts everyone and their dog downloads. Problem right there. A central connecting the BT network (which every non-LLU xDSL ISP will connect the home user to the ISPs network) goes through has a limited amount of bandwidth available. The maximum you can purchase is 622Mb/s. This soon fills up with users who download at 8Mb/s so then what happens? Natural contention will slow users down a bit as it begins to near 99% but after that packet loss happens. No one wants that. Do you want pings of 300ms+? Thought not. I like my 8ms echo reply to the BBC server.
Entanet asked the customers what they wanted. Nearly every person said they didn't want traffic to be prioritised. Nearly all said that something needs to be done. They all accepted that increasing bandwidth was not financially viable at £1.5million a year per central ($3,000,000 per year). Their end result was an Anti-Packet Loss Tool. They took the meaning of MAX DSL to its roots. 2Mbps+. If you get more great! On the ALT it will throttle every user down in 0.5meg steps until bandwidth is reduced to the point no traffic is lost. But this also ensures there is little wasted bandwidth available to the user. This tool will stop at 2Mbps, once throughput has reached acceptable levels (96%) than everyone's speed increases at 256k steps. They let everyone monitor this:
Entanet NOC » xDSL Central Pipe
Not sure why I typed this out as I'm sure you don't care about the UK's internet system. Although it is very likely to happen to you. I hope you are able to find a ISP which offers a good deal while being honest.