Bot farming is not allowed in ESO, as it's against the TOS. ZOS encourages players to report them and semi-periodically does a ban wave of known bots.
That being said, it's possible to bot in ESO with certain third party programs for the low cost of purchasing the base game. The idea for goldsellers is that it's profitable as long as they make more from goldselling than from buying a new account. Thus, ZOS trying to stem the tide of bots with bans isn't terribly effective. There's always more where the last bot came from.