One of the great ways to learn about your readers (and also for them to see that you genuinely care about their opinions!) is to create a reader survey. This is a survey that you’ll ask all those interesting questions you’ve been dying to know about from your readers, obviously, but it should also contain questions that help you to tailor your marketing efforts. Plus, it allows you to build relationships with folks along the way.
Note that I’m using Google Forms for this purpose. Here’s a link for you: Google Forms
Edit: Seems that the top of the video got cut off a bit, so here is a quick graphic that shows the top of the video.
And here is a video to show you how it’s all done!