I can't find the blog post, but some blog wrote a while ago why VCs invest in companies like Github. TL;DR -- basically it provides infrastructure for other startups.
The business itself may not be a great business due to the amount of cost it takes to run it -- but it's necessary for the running of other ventures.
The business itself may not be a great business due to the amount of cost it takes to run it -- but it's necessary for the running of other ventures.
Sort of like highways and non-toll bridges.