Gumroad is doing it and Pieter Levels also did it. Instead of spending a lot of money in buying ads you could run a little Giveaway experiment https://levels.io/giveaway/
To celebrate breaking $6M sent to creators last month, we're going to give $6,000 to a random person who retweets this tweet!
(you have to be following us so we can DM you if you win)
— Gumroad (@gumroad) August 16, 2019