Vertical integration is so clearly the best path when you are operating in technology, and especially when dealing with pure software plays. If you control everything down to the bare metal, no one can ever fuck with you. Your common denominator is your adversaries common denominator too. Only super exotics like Apple have actually captured a true 100% vertical down through the hardware, and the impact of this shows in the market.

Vertical integration can be a massive mistake too. Usually manifesting itself as rewriting external dependencies to use in-house functionality before you have established happy customers, cash flow and/or business value propositions.