[dale_glass]

It's not so much a cost cutting measure as a competition measure.

A given channel has only so much bandwidth. In DSL and the like, you can pick which part is dedicated to up, and which to down because you only have one pair of wires to work with.

So your link gives you say, 100 Mbps. You can split that 50/50, but then your competition can go with a 90/10 split, and look, their downloads are much faster!

[Karrot_Kream]

Right, it allows them to offer smaller pipes of 100 Mbit to users, which is a form of cost cutting. A true internet connection, the kind you'd get with your box in a colo or peering direct to an ISP or at an IX has symmetric uplink and downlink. The ISP is only willing to sell, say, 100 Mbit rather than the 180 Mbit equivalent a symmetric connection would provide.