Lawlor, 52, admitted four specimen counts of sexual activity with a child, seven of taking indecent photo-graphs and seven of causing a child to engage in sexual activity with another person.
He was sentenced to an indefinite term in prison, which will come up for review after 15 years.
Lawlor was warned by Judge Merfyn Hughes QC that, should he be deemed unfit to be released at that time, he may stay in prison.
The court heard Lawlor filmed many of the sex encounters, a number of which had taken place on Pensarn and Llanddulas beaches, and the activity continued even after a police investigation into his actions started.
Many of the men involved with the youngster, engaging in sex acts on the beach or in cars, were found through the adverts in Loot magazine or through the local "dogging" scene.
On one occasion, the girl was filmed too tired to continue, but ordered to carry on by Lawlor.
