Advertisers and marketeers are trying to sell something real (that might not be interesting enough to click), and aren't allowed to lie. Phishers are already breaking the law, so no worries about false advertising or dull products.
I'm not so sure about the advertisers not being allowed to lie thing. I worked as a minion at an ad agency for a brief time and pictures comparing the results of various products and such were from completely unrelated stock photos. I'm not sure I'd trust the text (copy) that much either, though it's a lot easier to catch them in it.