[rafaeltorres]

Interestingly, there’s a whole underground industry of services that provide this functionality by having banks of automated Android phones (not sure if physical or virtualized) to post on behalf of the user through the mobile Instagram app. Problem is you have to give them your direct Instagram credentials, and you run the risk of Instagram detecting this and banning your account (has happened.)

[herbst]

AFAIK this still can be fully virtualized, but you run heavy risk of a sudden spam detection change and resulting permanent bans.

Source: done it.