The claim that PayPal is "a must have" for e-commerce is misleading at best - the largest e-commerce sellers largely _don't_ accept PayPal (see, for example, Amazon) - and I would argue that isn't some weird coincidence.

> Some companies try to abandon PayPal and see a sharp decline in sales.

Removing PayPal is going to be way different than not having it in the first place, because you have cultivated a client base that expects to pay with PayPal.