Ummmm . . . not quite. Earthlink buys bandwidth from your phone company and resells it to you. No matter who maintains the last mile connection, you still need SOME kind of ISP, obviously. The prices are different now, but when I had ADSL, it broke down like this:
Phone company: (Verizon) ADSL 768/128, plus Verizon ISP service, $50/month TOTAL. This was the DSL connection plus e-mail, newsgroups, etc.
Earthlink: ADSL 1500/128 (through Verizon), plus Earthlink ISP service, $40/month TOTAL. This was the DSL connection (Verizon, purchased through Earthlink), plus e-mail, newsgroups, etc.
Note that the total cost was less money for faster service through Earthlink. I don't know what Verizon charges Earthlink for each ADSL connection, and I don't care. To me (the consumer), my total cost was less through Earthlink.
The prices are different now, but it wouldn't surprise me if Earthlink still has a better deal than the local phone company. And Earthlink isn't the only ISP. You might find an even better deal than that. My point stands . .. . if you want DSL, you don't need to deal with your phone company at all, unless you want to.
The local cable modem service is priced the same way. I can get (cable modem plus ISP) from the cable company for $60/month TOTAL or I can get (cable modem plus ISP) from Earthlink for $45/month TOTAL. In both cases, the actual cable modem service is from Comcast, and the speeds are identical. Guess which I'm using?
On any of these services, you can piggy-back another ISP. (but why would anybody do that?!?) For example, you could subscribe to "AOL for broadband", but that would be extra cost for service that you really don't need. If you were not an Earthlink customer already, I'm sure Earthlink would be happy to sell you service for about $20/month to use on your broadband connection, also. -Dave