You seemed to be saying that just like it could be muttar to tell one person, it could be muttar to tell the whole world online. And I was saying that that doesn’t follow.
Forget about whether it follows from your hypothetical, which I was not even talking about. Why isn’t it muttar? It is 1) not inherently negative 2) a piece of information useful for anyone making a purchasing decision. They can choose to save the money or consider other factors (distance, beauty of the store, etc.) as more important.