I think the best response is a simple “Thank you.” If you have better photos than the ones they’re complimenting, you might even say, “Thanks – I’d love to show you some of my better work too.” But always be thankful for the compliment even if you don’t feel the work is as good as they think it is.
What Sells Best On Shutterstock?
Some types of photos that sell best are Portrait Photography, Food Photography, Landscapes (usually with people) and fine art photography (artsy).