Amazon is the Walmart of the internet.
You're joking, right? Walmart, for its entire history, has been targeting low income folks with poor to fair quality products. Sure, Walmart has sprinkled in some nicer (and albeit very common) products such as iPods and iPads and some select tvs. There's also the clientele that shop at Walmart that has spawned thousands of "Walmart shopper" videos displaying some really trashy and freaky people.
In general, when you call a company "the Walmart of ______" you are really calling that other company a bad name. Like a trashy store. I don't consider Amazon remotely close to Walmart as far as quality of products, vastness of selection, and by far superior customer service and experience.
Amazon has been the king of online retail for a long time...and will likely dominate for even longer. Amazon sells everything. Everything. The first place people search for a product is Amazon...not Google.