Merchandising is a strategy to have in your back pocket if your indie game gets successful, albeit it is a bit of a long shot as not every indie game becomes so famous that it can command its own line of plush toys and branded yo-yos. Products might be as simple as branded stationery and posters or as complex as a whole toy line with a TV program to promote them. You shouldn't impose merchandising, but it's a great method to make money off of your independent game. The audience, not you, must determine if your game is worthy of its own series of Funko Pops.
For more details, read How Game Developers Make Money (Top 10 Ways).