Well, for all of those things, what is expensive for a small company if you run it yourself is the sysadmin aspect. You could run all these services off of a pa

Well, for all of those things, what is expensive for a small company if you run it yourself is the sysadmin aspect. You could run all these services off of a pair of three-year-old servers from ebay for next to nothing in hardware cost, even if you buy cold spares for disks and fans and power supplies from the get-go. But the cost of having someone learn to install, configure and operate all this software is very significant. But when you're at the large scale and offering this as a commercial service, you've designed your free tier such that the marginal cost of adding a free tier customer is essentially zero, and the best way to acquire new customers is to have someone in that org using your product's free tier for their personal projects.