Boycotts bring wider attention and support because under capitalism, purchases make up a significant component of daily life/entertainment. They are also a metric of that support.

By running in-person tabling in boycotts, you create a means by which to build connections and movements, particularly if you do so under the banner of a socialist organization. You may be surprised at how unaware most people are, yet open to talking about it. The core organizing issue is why the boycott is being called for. The anti-apartheid movement succeeded in moving the dial in the imperial core through this tactic.