The novels, and the TV adaption, are set in Scotland and feature locations including Newtonmore's Highland Folk Museum and Doune Castle near Stirling.
The properties' owners flag up the connection, while other people make and sell crafts influenced by Outlander.
Gabaldon said: "It is like a cottage industry. It is fabulous."
She added: "There are Outlander tours and also people making things based on Outlander and selling them on the internet, besides the official merchandise.
"I never imagined while writing the stories that they would inspire people to do this."
Gabaldon's work has been used to attract tourists with VisitScotland producing an online map of Outlander sites.
Last year, the Highland Folk Museum held its first day dedicated to the books and TV series, which uses the museum's reconstruction of a 1700s township for scenes.
The owners of Doune Castle also flag up the Outlander connection on their website.
A second season of the TV adaption of the novels has started on Amazon Prime.
Outlander follows the story of Claire Randall, a World War Two nurse who is mysteriously swept back in time from the 1940s to the 18th Century at the time of the Jacobite Rising.
The latest season features the Battle of Culloden near Inverness.
The 270th anniversary of the clash that saw a Jacobite force led by Bonnie Prince Charlie defeated by a government army on 16 April 1746 will be marked this weekend.
Gabaldon said that the new series coming at the same time was a coincidence.
She added: "The anniversary will hopefully give historical context to the new season.
"The Battle of Culloden will be shown and the show's makers have done excellent work in re-creating a large and difficult battle."
The second series of Outlander is available for Amazon Prime members with new episodes released every Sunday.
Outlander author Diana Gabaldon said she never imagined her stories would be used to boost business and tourism in Scotland.