One clever way of participation that I noticed and it actually worked on me is through social media platforms such as facebook, instagram and twitter. They do not force the ad on anyone but it just pops up. Especially an ad that pops up multiple times. For example I was scrolling through instagram and I kept seeing the same ad for a game called Toon Blast. It was a video so it looked like someone was playing it and since I saw it so many times I went and actually downloaded the game. I think using the social platforms is a good way to advertise because it is not force because it is not like the user has to look at the ad but instead it is just subtlety on your feed