Cheaper than competing, ATT CLEC owned what is now Comcast at one point in time.
AIUI, AT&T CLEC split off the cable part, which became Comcast. Unsure where ATTBI fit in that scheme of things.
Verizon is not a CLEC, though, but an ILEC; same as the old SBC, which is now the "new" AT&T. -- Norman ~Oh Lord, why have you come ~To Konnyu, with the Lion and the Drum