So, back in 1994, my dad and me started an ecommerce company (bikeworld.com) that sold bicycle parts online. It was an extension of his brick-and-mortar bicycle business and I took a couple of years leave from college to help him build it.
He did one thing early on that generated amazing word-of-mouth support: send a little treat in every order box. Our company was based in San Antonio, TX and Dad decided to include a little local flavor with each order to make us stand out from the few competitors we had back then (incumbent mail order outfits). At every good Mexican restaurant back home, they sell Mexican chewy candies at the cash register when you pay after your meal. My dad and I loved these things so he went to the manufacturer in town and bought a few cases of them. They were really expensive, like $0.50 each, and it became a big expense but the customers went nuts. Dad printed up a little card that he put in the bag with the candy, explaining the tradition and thanking them for their business. It worked well--we quickly became one of the largest online bicycle stores of the late 90s.