> That said, yeah it's difficult to understand how KA's web server costs aren't already basically zero, and how their endpoints aren't already basically instantaneous.
I find that this is the outsider's view of a great many products. Things always seem a lot simpler on the outside.
In Khan Academy's case, I think a lot of folks just think of our site as being a collection of more-or-less static pages with videos on them. There's a lot more going on than that, though. We've got a CMS that supports articles with math and interactive elements, in addition to the videos... and many, many exercises with hints. All translated into dozens of languages.
We have to remember every exercise people have done so that we know which ones to present to them next, and we need to display that progress when they look at topic pages. Oh yeah, and if they're in a classroom, we need to present that progress to teachers (or coaches/parents, outside of the classroom). Teachers can also assign content.
Plus, there's the official SAT prep, which connects to the College Board directly to provide personalized guidance about what to work on... and that's only one of the test preparation areas of our site.
And, as you can imagine, there are a bunch of other features and aspects of the features above that I'm not mentioning. It adds up.
Fair, but what percentage of spend is actually on web servers as opposed to database, data transfer, static asset storage, caches, CDN, etc? The features you listed are kind of what I expected, but I still wouldn't expect the web servers to be more than 15% or so of your hosting costs. I know you guys get a ton of traffic, but on most web sites at least 90% of traffic is logged out and doesn't even need to hit the web servers in the first place.
I don't have recent numbers in front of me, but I believe our web servers are more like 40% of our hosting costs today.
Over the past year, we've started leveraging our CDN (Fastly, who have been great) a lot more. That said, for us a lot of logged out traffic still carries the weight of logged in traffic. A logged out user can start doing math exercises and we'll keep track of what they've done. If they then create an account or log in, that activity is associated with their account.
Khan Academy may look like a content site, but in many ways it's more like a "learning app".
I find that this is the outsider's view of a great many products. Things always seem a lot simpler on the outside.
In Khan Academy's case, I think a lot of folks just think of our site as being a collection of more-or-less static pages with videos on them. There's a lot more going on than that, though. We've got a CMS that supports articles with math and interactive elements, in addition to the videos... and many, many exercises with hints. All translated into dozens of languages.
We have to remember every exercise people have done so that we know which ones to present to them next, and we need to display that progress when they look at topic pages. Oh yeah, and if they're in a classroom, we need to present that progress to teachers (or coaches/parents, outside of the classroom). Teachers can also assign content.
Now, we're also offering features for school districts: https://www.khanacademy.org/district
Plus, there's the official SAT prep, which connects to the College Board directly to provide personalized guidance about what to work on... and that's only one of the test preparation areas of our site.
And, as you can imagine, there are a bunch of other features and aspects of the features above that I'm not mentioning. It adds up.