Now the site has graduated and the user count increased, there is no need to artificially create popular questions. As I predicted before :
Once we reach the critical mass, those question will be generated naturally by users.
I think we reach the critical mass, as we saw recently with the post credit scenes questions. Though, it's still good the have incentive to make sure we are the first to get those question on new stuff.
Here my reasoning:
A nice question is a clever question that tends to get lots of attention when it shows up in the main page. It usually shows up in the Hot question Stack exchange list and typically gets a huge boost of views in a short time, but then slows down to almost no views, like a logarithmic curve.
A popular question is less clever, but it's something that the lambda user is more prone to ask. Those questions won't necessarily get a huge boost of views at first, but they constantly get views. Days after days, after days, like a linear function.
I came to that conclusion after seeing what was happening to one of my own questions : Why did Harry Potter intentionally lose the Resurrection Stone in the Forbidden Forest? . In fact, this question was inspired by a comment by gunbuster363 on Was Harry Potter killed and then brought back to life? I knew the answer, but I did not have the time to properly answer the comment. Anyway, that led to my most "famous" question to date and it's still constantly getting views.
So, although those views came from Google users that simply type the question and land on our site, it led me to ask the first other obvious Harry Potter question I could think of : Why did Harry Potter break the Elder Wand? as an experiment to prove my theories -- and it worked! This question is also constantly getting its share of views, slower than the previous, but still at a decent rate.
I think we need more questions like this. They would lead to better visibility for the site and and more users. But I don't know where to start. For example, if I type "does Harry Potter" in Google, it suggests thing like "does Harry Potter die" and "does Harry Potter kill Voldemort", but I have no idea how often those question are asked through Google.
Does anyone know how to get those numbers, or any other way to get more Popular Question?
After reading some of your answers, I think I need to be more precise why we need more "Popular Questions".
Right now, the site didn't reach is critical mass. If we look at the Area 51 metrics, the 2 main sections on which we need to improve are
questions per day and
visits/day. I think we already attracted a solid base of core users who could amazingly answer the questions that are asked right now. What we need is more questions from newbies. But to attract those newbies, I think we need more "Popular Questions". Once we reach the critical mass, those question will be generated naturally by users.
There's also the fact that for almot all ours users, scifi.stackexchange is not their first account on the network. We need to diversify our recruitment sources.
Google's auto-complete was just the first thing I thought of to find those questions. And I dont think we should seed the site with question like "Does Harry Potter die in the last movie?". I just think that a quick look on popular search queries that include some of our topics could lead to good questions.
It's the same when you browse the Hot question list. There are always those questions that "I always wondered why , but I never thought of asking." (For me, programmers.stackexchange is specially good at this).