You need to own and exploit a monopoly in order to grow into a true tech heavyweight. Facebook has social (and all the traffic and user data that comes with it), Microsoft has the OS and utilities, Apple has the OS, hardware, and apps, and Google has search and (tbd) Android apps. Unless you monopolize something of extreme value (user data or a platform), you should focus on just making money, although unfortunately…
If Facebook "has social" that's because they were and still are the best social network. Of course, now that they are big, they've got a huge lock-in effect, but that's besides the point. Microsoft "has the OS" (and I might add Office) because Windows really has been the best general purpose, generally available OS. Other attempts had potential, but they either keep failing to be as polished or stable for end-users (desktop Linux), or have not been available for all PCs (Mac OS, OS X), or they didn't survive for long enough (OS/2, BeOS). Not sure what monopoly Apple has, but it's no point in arguing that most of what Apple does is technically excellent and beautifully executed. Google "has search" because they had and still have the best search engine and their search engine is indispensable for most people. People talking about DuckDuckGo never tried doing searches from outside the US. Google also has Android, Gmail, Calendar, Docs and Maps, all of which are excellent.