I used this to my advantage awhile ago when I needed rent a moving truck. Penske called me about 30 minutes after I abandoned their online rental process. After a bit of back-and-forth about why I aborted the rental, Penske offered me a discount that beat their competitor's price.

I've since used this technique a few times to my advantage when renting trucks. So, it can be a downside for the business if customers catch on, unless it's considered part of doing business.