Bests & Worsts Reviews from Amazon

I've had two pit bulls and they loved the Kong frisbees. The ones I bought in the brick and mortar pet stores lasted for over a year each, provided I just used them for frisbee catching and of course a little tug of war after my dog returned them to me. Even with a tiny bit of tug of war, the frisbees held up fantastically and I could throw them straight consistently for 30 to 50 yards with no problem. Now I've bought two or three over the past year through Amazon and they have all seemed to be pretty flimsy. And they never fly straight any more. Is it a coincidence? One frisbee maybe, but not two or three. I love Amazon. I buy 90% of my stuff through the company, but I've been burned by counterfeit Apple charger cords and Gillette Mach 3 razor blades (http://www.amazon.com/product-reviews/B0039LMTHE/ref=acr_dpxrating_hist_1?ie=UTF8&filterBy=addOneStar&showViewpoints=0). I'm starting to lose confidence in the authenticity of their products. If Amazon can't verify the integrity of the merchandise being sold on its site, then they should not sell. My apologies if I'm wrong, but I've never been given reason to question the supply chain with any other brick and mortar retailer in the past.