Pretty much every company outsources some part of its business. My company outsources our deliveries (would not be cost effective to maintain a Worldwide fleet of trucks and aeroplanes to deliver our products to our customers). We also outsource our injection moulding and PCB manufacture (volume not high enough to supply permanent work to an in-house facility). We also do not run our own telephone company or ISP, though we do run our own server farm.
ISTM that the first outsourcing that took place was when the government outsourced to Vodaphone rather than keeping it in-house(ish) by using BT.