I post links to sales all of the time. Apparently it's not a problem unless it's the merchant themselves posting it, then it's considered advertising and has to go in another forum.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi