Is it? It's tough to say whether the wording was the problem in your case without seeing the site though. Was the link visibly clickable? Was it a button? What would happen if it was a button and it had a Living Social logo on it? Bold text calling out to click sounds more visible and enticing, but there are other ways to grab users' attention.

Yes, you can print an A3 sized sign to remind visitors to flush the toilet, bolding, italicizing and underlining the text to get their attention. Or you can make a clever doodle or an icon, and make it fit into the bathroom's interior design.