What are some essential (marketing) tasks to get new users after launch?

After the initial wave of users after launch dies down, what are some good ways to keep attracting new users?

I like to write in-depth blog posts that solve an issue your customer having. So if you have frequent customer questions or are trying to solve a pain point, figure out what they would google and write a better article than the #1 ranked result. (Sounds difficult but can be easier on long term keywords)