Its not only Sky that do this BT to also does it.
A friend of mine had a visit from a BT salesman that told him if he took out ADSL2 with them he would be guaranteed 24mb. He said he would think about it and took the sales persons number, when he checked online it stated his line could take a max of 6.4mb with BT but he eventually went with Sky and he gets around 9mb.
He just signed up for sky fibre so see how that goes.
AMD FX-8320 X8, MSI 990FXA-GD80, 16GB DDR 3 Cosair Vengence 1600Mhz, 9351.1GB Hard Disk Space, 2GB ATI 6670 HD PCI-E 16x Graphics, 850watt PSU.
Ex AOL Dialup 56k Customer....
Ex Freedom2Surf 512k and Ex Eclipse Internet 2mb Customer.
Virgin Media 152mb Cable.
Virgin Media R EVIL!!!