Write an article for a magazine. Self-promotion does not pass solely and exclusively on the web: being able to get a couple of articles from specialized magazines published can be the concrete signal that the idea behind your essay is not only good but is also worthy of great attention and therefore, we hope, also of some commercial success. Or you can also try yourself at some essay writing service and become an AU assignment helper. If you have already created a mailing list for your blog, remember that it never represents your target market in every way. That is why it would not be a bad idea at all to send a survey to your potential readers, asking them questions about the subject of your book. This is the easiest and most immediate way to find out if your readers are interested in that type of content. Organize a free webinar. Technology makes it very easy for us to organize all kinds of webinars on every possible theme, so why not take advantage of it? Just create an event and promote it through your mailing list and social networks: if the event registration is high, it is very likely that the theme chosen is of great interest. This is already a great result that you can make even more useful through a series of questions and surveys that you will submit live to all the participants of the webinar. Needless to say, how important it is to understand their tastes and interests!