Or you can do both.
> Your refusal to not consume it isn't going to change them buying the plastic, because given the choice, people aren't going to stop sampling in the aggregate. And at that point you're just signaling to other people in a really silly way.
This is a strange viewpoint to me. Acting based on your principles in your day-to-day life isn't just about signaling to others. It's about how you live your life, and acting "in tune" with your beliefs can lead you to profound happiness. If you decide that single-use plastics are bad for the environment, and you like the environment, then you try to avoid them. It's pretty simple.
But I don't even think that signaling is silly. Some people are convinced more by actions than words. I've reduced the amount of waste I produce by bringing containers to get stuff from bulk foods sections, literally because I saw someone doing it and realized it was possible. Before that, I would've thought "oh man it sucks that you have to get granola in single-use plastic, but oh well, that's life." As strange as it sounds, I had never even considered bulk food sections, even though I know the mantra "plastic bad".
If you extend your arguments, they imply that acting based on your principles in day-to-day life is pointless (or merely "posturing") because we are all small and insignificant, and the only thing that matters is trying to change laws. But I think you have it partially backward. People acting on their strong beliefs and spreading those ideas to others is what eventually invigorates political changes in the first place.
If you really care, talk to your local representatives or write to Trader Joes and Whole Foods. Anything else is posturing. Not taking a sample which costs them a few cents on the dollar is not taking action.
I'm not going to stop, personally. They can give it to me in paper wrapping instead if they want to make a difference, and in fact, with their cups, they already do. Let someone invest in paper sampling spoons.