Do boycotts work anymore?
It seems like of late boycotts have returned to the en vogue way of attacking a company or movie with owners or creators one dislikes. But, then people on the other side of the issue see the talk about a boycott and step up their business. If anything, then it seems like the boycott target ends up doing better not worse.
In most cases the target of the boycott was doing okay, but not especially well. People had mostly forgotten it existed. The boycott essentially gives it free publicity. My guess is people who like the business but dislike the stance of the issue will be torn. Some will stop giving it business, some will pull back some, and most will stay about the same. The supporters of the issue will swarm it.
Probably good that I am not a marketer, because I would be willing to dabble with a guerrilla marketing campaign where I poll how people feel and instigate boycotts against my client.