Like grocery stores or many types of restaurants, for example. They usually can't compete against the Walmarts and Paneras, which suck up consumer mindshare. Similar with soft drinks. Coke and Pepsi build as much mindshare as possible. You may invent a great product, but it likely will never get noticed among corporate noise.
Google, Wikipedia, Facebook are becoming the default go-to spots for particular activities, similar to what McDonald's did to fast dining in the 60s and 70s. I guess, in general, markets saturate, oligopolize, and the small spots fade away unless they're niche or very high quality.
