That's called hunting. Hunting is a time-honored tradition, but no civilized country feeds itself by hunting anymore. We're now a planet of farmers, and farming is the only scaleable, predictable way to feed a population. The problem is that while everyone else has figured that out, marketers haven't.
Marketers are still hunters.
So they load up the gun and go hunting. However, now consumers have more power than they ever did. Now the cost of interrupting somebody, which is a form of hunting, is higher than ever. And now, due to the Internet, where there are 40 million sites to choose from, the chances of you getting an unlimited supply of people are very small. Marketers online need to become farmers.