Jason Piontecki, 32, from Swansea, pleaded guilty to nine counts of sexually abusing children under the age of 13 over a number of years.
Swansea Crown Court heard the young victims had been massively affected by what had happened to them.
Judge Paul Thomas said: "The long term damage at this stage is incalculable."
The court was told chat logs were recovered which showed Piontecki discussing the abuse with others online and that there were graphic details of others viewing the abuse and explaining what they wanted to do to the children.
Judge Thomas told him the chat logs were "stomach churning".
"What the chat logs make all too horribly clear is that you didn't just do this for yourself but for others too," he added.
"Your perversion was such you lost restraint."
Piontecki was arrested earlier this year following an investigation by the National Crime Agency (NCA).
He will serve two thirds of a 15 year sentence and has been ordered to sign the sex offenders register for life.
Colin Radcliffe, from the NCA's child exploitation online protection command said: "Jason Piontecki led a seemingly normal life, however his sexual interest in children could not stay hidden and has ultimately led to his downfall."
A former hotel manager who sexually abused children on a webcam for other paedophiles to watch has been sentenced to 15 years in prison.