There's a book called 'Information Foraging Theory' written by Peter L T Pirolli, published in 2007. Despite its age, it's an mine of information that is mostly still relevant today. In short (I'm reducing 216 pages to a sentence here), it says that users will go as far as they need to, and click as many times as they need to, as long as the scent of information' is strong. In other words: as long as a person thinks they will get the information they need, and they don't think they are on the wrong path, they will continue for quite some time. You can use this for structuring the information on your website, in-page copy, and tools and transactions. As long as you follow your audience's mental model of how the information will be available, and you provide a strong scent of information, you are on the right path. That's not an excuse to be verbose. What I'm saying is: people don't always abandon a task within a set number of clicks.↱
Content Design
Sarah Richards