Fortunately there is a CAN-SPAM act which means we don't have to rely on what the sender or the community thinks is reasonable. Advertisement of a commercial pr

Fortunately there is a CAN-SPAM act which means we don't have to rely on what the sender or the community thinks is reasonable. Advertisement of a commercial product or anything on a website operated for commercial purposes requires "express consent to receive the message, either in response to a clear and conspicuous request or at the recipient's own initiative". Pretty far from "putting it in a public space", then.