You can bash Amazon all you want, but they do a lot of things better than many other companies.  I would like to support smaller companies and ones that are more USA oriented, but sometimes they make it hard.
I needed some special bolts and nuts in stainless.  I could have ordered them from Amazon and gotten them two days later but found a place I have used before.  Both were nearly the same price.  In fact, I think Amazon would have been a little cheaper.  But, I went with the other guys, just because.  I placed the order on the 25th.  I did not get any kind of notification of the order other than on the web page when I placed the order.  Two days later, I emailed them with the order number and asked if I would get any tracking information.  The next day I got an email response back with tracking information that said it was shipped.  Three days later and the tracking with USPS shows:  "Pre-Shipment Info Sent to USPS, USPS Awaiting Item".  So, in reality after 4 days, it has not even shipped. 
With Amazon, I would have had it two days ago, yesterday at the latest. 
So, yah, that is why Amazon is one of the biggest corporations in the world in such a short time.  Selection, low prices and fast delivery.  Oh, and their return policy is very good too.  That makes it tough to go with some of the other local B&M places and smaller suppliers.