What it actually does
Enter a seed term and AnswerThePublic returns the ways people complete that phrase in search: questions beginning who, what, why, when, how and can; prepositional phrases with for, with, near and without; and comparisons using versus, or and like. It presents them as a radial wheel, which is memorable and mostly decorative, or as a plain list, which is what you will actually use.
The value is coverage. Given a topic you already know is worth writing about, it takes about ninety seconds to see the full shape of what people want to know: including the four or five questions you would not have thought of, which are usually the ones that make a page more complete than its competitors.
The limitation that defines it
It shows you questions, not demand. There is no reliable search volume and no ranking difficulty, so the tool cannot help you decide whether a topic deserves a page. Used alone, it produces meticulously thorough articles about things nobody searches for.
Which makes it a companion tool. Decide what to write with Keyword Planner, Trends or a paid suite. Decide what to cover with this.

