> please kindly explain to me how you forgot there are other shops.

I will provide one anecdata. Often times the first place I look for the existence of an item is Amazon. That is if I want a certain cable, I do not open and search 5-10 different places (overstock, target, bestbuy et al). I just go to amazon and choose from what they have. There may be better, there may be cheaper, but unlikely with a sufficient margin to compensate for the overhead of searching more places, learning more nuances (return policy, shipping) etc.

Well... there's a thing called the "literal meaning" and sometimes there's another "figurative meaning"... and as you grow up you'll end up knowing the figurative meaning of a phrase quicker until it's second nature.

For the same reason people who use Facebook tend to forget about people who don't. Convenience is sticky. Amazon, like Facebook, spends a lot to subsidize that convenience and thus that stickiness.

It's the online equivalent of the Wal-Mart effect.

Many people who shop online have only become online shoppers after Amazon became the dominant online retailer. For some people, Amazon is online shopping.