A fair bit, yeah. I usually buy my motorcycle tires through Amazon, because they’re almost always significantly less expensive than better retailers like Revzilla, Dennis Kirk, and so on. My last set of tires was about $100 cheaper after shipping. When I was shopping for shoes (Vibram FiveFingers), Amazon had the widest selection in my size, including prior model years.
But given a real option, I’ll usually prefer to shop pretty much anywhere else.