Interesting, but consider that, in general, they probably <i>did</i> outsource some aspects early on, and learned the lessons needed.  In most cases, the example you give are just too large for anything they do to be outsourced to anyone else - few other companies operate on Amazon scale.<p>The &quot;outsource everything&quot; mantra may also be fueled in part by VC firms who also just happen to be funding a bunch of other companies that... look at that... provide some of the services you should outsource.  Many years ago, on a small scale, I had discussions with a small VC firm.  In exchange for their investment, we were also expected to use some of the other companies in their network whenever possible (media&#x2F;marketing&#x2F;other tech&#x2F;etc).  That seems a bit of an extreme scenario, but i can&#x27;t imagine this doesn&#x27;t ever happen at all.