The best ethical strategy is to use offline media buys to influence the search pattern of users. Working in big agencies where you have combined teams working on various verticals it is some times hard to leverage SEO into the mix, yet once SEO is at the forefront of these campaigns you can really work wonders.
I have not really seen any killer examples of this in play yet, but many companies in AUS are trying these methods.
As Dejan SEO said you just need to get the right messaging in play.
Regards,
James Norquay