A lot of times I buy for the websites of big name brick and mortar stores. Some B&M stores also have third party sellers, so watch out for that. Walmart.com offers free two day shipping for orders over $49, which I've used quite a bit since they implemented that policy. I've also bought direct from the manufacturer.

As far as jet.com, I think their suppliers vary and I don't know if they have better vetting of their suppliers. They are owned by Walmart now, FWIW. I've bought a few things from there and they have very bad problems with packaging, all my orders had something destroyed during shipping due to poor packaging.