DNS doesn't occupy a lot of bandwidth. DNS servers on the other hand can be irksome to deal with if you don't have to. Small ISPs are merely resellers; if thei

DNS doesn't occupy a lot of bandwidth. DNS servers on the other hand can be irksome to deal with if you don't have to. Small ISPs are merely resellers; if their DSL customers f'rinstance use Google's DNS servers instead of the ISPs, the ISP actually has less network traffic coming into their racks. Plus, they no longer have to admin a DNS server. For larger ISPs, it may still be less trouble to just let their customers use Google's DNS instead.