Joseph Cunningham, 51, was told by judge Lord Pentland that his conduct was "calculating, manipulative and controlling".
He admitted carrying out the horrific offences at various addresses in Dundee in the 1990s when his young victims were aged between 11 and 16.
The High Court in Glasgow heard that Cunningham bought one of his victims a bike and allowed him to smoke and drink alcohol. He also convinced the boy his parents didn't care about him.
Cunningham blackmailed two further victims by photoshopping fake pornographic photographs of them and blackmailing them to perform sex acts.
He told them they needed to pay him £30 to buy the photo off him or he would place them in phone boxes.
Jailing Cunningham, Lord Pentland said: "Each of your victims was a vulnerable child of whom you took advantage for your own sexual gratification."
His defence QC Brian McConnachie said: "He has very little recollection of these offences, apart from those involving one of the complainers because he believed he was in a relationship with him."