The musician, who moved to Brighton four years ago, said his week had been "pretty mind-blowing" since hearing the news.
"We did a good job on this last album and managed to market it in the right way, reach the right people and we can be happy," he said.
Marriott explained that Don't Tell the Dog was about about moments in his adulthood that resonated with his childhood, taking inspiration from his late dog, Jasper.
He says his tip for success is to be "honest with your artistry" and to make content online that supports your music to help "get your art out there as much as possible".