I got my sponsorship by being persistent. It’s a fairly small sponsorship. 25% off anything in the store, but 25% off of supps over the years adds up.
When I first approached them they said they weren’t interested, I approached them again with some more information, my projected list of supps that I would buy on a monthly basis, my videos, and ideas of ways they could “use” me. They agreed and have been shopping there almost exclusively since.