Basically, it's luck of the draw.
There are a number of factors which can go into how many views a question gets. The most important ones I can think of are as follows, in (IMO) decreasing order of significance.
- Hot Network Questions.
- Search engine results.
- Promotion elsewhere.
Hot Network Questions
This is a list of questions from all across the network, changing all the time, according to what's currently 'hot'. The precise formula for 'hotness' can be found here, but the TL;DR is that if you get lots of answers/votes fast, you're likely to get on the HNQ. Either more than one answer with a few upvotes, or one answer with a lot of upvotes, soon after the question is posted will be a likely recipe for HNQ.
The HNQ list skews votes and views massively. When a question hits the HNQ and stays there for a while, it can get 100+ votes and 10,000+ views in just one or two days. Many of our badges called Great Questions, Great Answers, and Famous Questions come from posts which hit the HNQ (and sometimes their quality doesn't really reflect the score or the badge name. As another mod once said, "popularity does not equal quality").
Search engine results
The above is usually the explanation for a post getting lots of views fast, but there are also slow-burners: questions which never hit the HNQ but got 10,000+ views anyway, or were posted long before the HNQ system existed, or just gathered thousands of views over a period of years. This is probably because people's web searches lead them to that question. If this happens to you, then congratulations - you've asked something that's useful to the wider internet!
Anecdotally, I've observed this effect especially strongly with suggested-order questions. The most-viewed question on the entire site, by far, is about watching order for the Star Wars films; and the most-viewed question in each of many different tags is also about reading or watching order. To a lesser extent, I've also seen it happen with story-identification questions, e.g. this one which was closed soon after being asked and never hit HNQ, but has gained 10,000 views since then. All of this makes sense, of course, because order and ID questions are among the most practically useful on the site. People might be idly interested in what Tom Bombadil was, or why Hermione wasn't in Ravenclaw, but helping them to find a lost story again or to know in which order to read a series will actually have an effect on their lives.
This one is much harder to track down, but apparently it can also have an effect on views for particular questions. If a post gets promoted somewhere else, e.g. an offsite blog with a lot of traffic, then it might pick up a lot of views from that. That's what happened in this case previously asked about, and it's probably also the cause of most of our Publicist badges, but IMO it's the least significant of the three effects listed here.