# What makes a post go viral?

Looking at the main math.se page, we see a list of questions with basic information about them - including the number of views. That number of views can vary quite wildly. An interesting question from a few years ago might have been have been viewed only a few times while a question from just yesterday might have been viewed a few thousand times. What accounts for this? I'm guessing that it's social media but I'm curious how to find more information on that.

Here are a couple of examples of questions that have been viewed several thousand times each in the past couple of days:

I guess both questions are kind of cute and accessible, but I wouldn't call either exemplary. My impression is that they've been highlighted on social media. Is there any way to find prominent links that are pointing to these or similar questions?

• Once a question gets into the HNQ, it's self-reinforcing (for a while). – Daniel Fischer May 23 '16 at 15:57
• @DanielFischer Thanks! I'm aware of the Hot Network Questions and I'm sure this counts for something. I'm guessing thousands of hits in a day are coming from somewhere else, though. – Mark McClure May 23 '16 at 16:07
• – Martin Sleziak May 23 '16 at 16:10
• @MartinSleziak Thanks! Looking at Willie Wong's answer there, it appears that he discovered the links using his (then) 'Mod Superpowers'. That suggests that there are, in fact, tools for finding the links I'm curious about, but that they're available only to moderators. – Mark McClure May 23 '16 at 16:14
• I am not sure, but reading his answer he might be referring to site analytics, which shows sources the traffic on the site. But AFAIK it does not show this information for specific questions. – Martin Sleziak May 23 '16 at 16:17
• sometimes a questions gets quoted and linked on some large general purpose site, there is one called reddit I have never seen. When that happens the views get enormous, possibly the votes. – Will Jagy May 23 '16 at 16:40
• If you want to find links, just search for them. :-) Most of the time a link will include the question-post ID number. Feed this number to your favorite search enging and maybe throw in a "stackexchange" or something. Or search for http://math.stackexchange.com/questions/{IdNumber} and http://math.stackexchange.com/q/{IdNumber} This should cover most links. You could miss out some, if somebody where to specifically link to an answer, but this is rare in such cases I think yet you could include those if you really care. – quid May 23 '16 at 16:50
• In the two specific cases are not that extreme and I think it is mainly just HNQ, for now. The former may have potential for more. – quid May 23 '16 at 16:53
• @quid I guess you mean search for them in Google or your favorite general search tool - not in the math.se search box. Thanks! That does turn up a few interesting things. – Mark McClure May 23 '16 at 17:04
• Yes. This is what I meant with "search enging" (which should have been engine, of course). – quid May 23 '16 at 17:10
• Funnily, by just inserting links to those questions in your post, you have contributed to increasing their popularity. – Alex M. May 31 '16 at 16:48
• @AlexM. True - a little like an observer effect. :) Also, I notice this post has been receiving upvotes since, for some reason, it's made it to the Hot Meta Posts list. – Mark McClure May 31 '16 at 17:03
• @MarkMcClure Do men or women have more brothers is an exemplary question because it challenges some of the fundamental principles of statistics. – samerivertwice Jun 1 '16 at 14:33

Being in Hot Network Questions can easily provide thousands of hits in a day. A random selection of "hot" questions appears in the sidebar on every page load on every SE site (except MathOverflow). Stack Overflow has 505.9 million pageviews in a month (compared to 9.1 million for Math.SE), and its audience consists of people with above-average mathematical training. Even a small percentage of SO users clicking one of a few selected questions drives up their traffic.

As of now, Math.SE is represented in HNQ by 6 questions, which include both of those you mentioned. Here they are in the order of decreasing "hotness":

1. Do men or women have more brothers?
2. What am I doing wrong in calculating the following limit?
3. What is a topological space good for?
5. Does this Fractal Have a Name?
6. How to find kernel and image?

The recipe for getting in HNQ list consists of having a catchy (or vague, clickbaity) title, an accessible question statement, and several answers given quickly.

Questions do age out of HNQ list in a few days, so their long-term traffic depends more on their search rank and the links from outside the network. For now, as far as I can see, HNQ is responsible for the traffic to those two questions.

• Thanks! I suppose I underestimated HNQ. Also, I was curious about this question. My answer seems to get a a few hits a month. To my surprise, I searched for discontinuous derivative (and a few variants) on Google and that question was the first hit. So search engine traffic probably is more relevant than I realized. – Mark McClure May 23 '16 at 17:27
• @MarkMcClure somewhat along these lines, you may be interested in a post exploring high Google ranks of MO posts. – quid May 23 '16 at 17:50
• Another important ingredient to get inducted into the HNQ hall of fame is to avoid using Mathjax in the title, which in many cases means that a non-descriptive title will be rewarded with quite a lot of attention. The HNQ list might therefore be a good place to start if you're in the editing mood. – Daniel R May 23 '16 at 20:15
• Can anyone tell me why not Math overflow has a HNQ sidebar ? – A---B May 30 '16 at 8:32
• @ritwik, their format predates SE 2.0; I am sure the regulars there will have a fit if they see anything like that HNQ nonsense. – J. M. isn't a mathematician Jun 4 '16 at 1:18
• @ritwiksinha MO founders have an agreement with SE, which in particular stipulates there will be no promotions of any kind on MO. See meta.mathoverflow.net/q/1232 – user147263 Jun 4 '16 at 4:06
• @sandwich Why no promotion ? didn't they are using a tool by Stack Exchange. – A---B Jun 4 '16 at 6:29