This holiday season, Amazon offered price cuts on almost all holiday gifts; it can do this in part because of its size and profits from other businesses, like cloud computing, analysts said. The company offered free overnight shipping on thousands of items, and advertised its price-checking app by giving shoppers 5 percent off items on Amazon that they scanned in a store.

Amazon says it is giving consumers what they want. But the price-check promotion drew special ire; Senator Olympia Snowe, Republican of Maine, called it “an attack on Main Street businesses.”

It is contributing to “a reputation as a bully,” said Sucharita Mulpuru, an e-commerce analyst at Forrester Research. Reflecting that, in a reaction similar to what occurs when Walmarts open in small towns, some consumers say they will not support supersites any longer. But the economics of that decision are not always sound, said Professor Walden of North Carolina State. If a small site is selling products from a national manufacturer, for example, to people scattered around the nation, it has little effect on local vitality, he said.

Dr. Pollack, the Chicago professor, says that even if he is not supporting Chicago retail with his online purchases, he is not supporting what he calls big business’s bullying ways.

Emily Powell, the chief executive of Powell’s Books in Portland, Ore., which has an e-commerce store, said she attracts some shoppers with similar attitudes. “People come because they want to support an independent and feel good about it,” she said, but especially in a recession, “you can only guilt people into coming to you for so long.”

That’s where the other strategies kick in.

Some stores respond by carrying exclusive items at their sites. Powell’s Books, for example, offers a subscription service through which it chooses a new book and includes an extra item like a related book or candy — personalized touches that it says big sites can’t match.