Control the internet, you can have an impact.

Download the alexa toolbar (no I don't work for Alexa - honest), this way, the sites and types of
sites that you like will get better rankings on search engines that take into account Alexa rankings when returning results. It may only be a small effect but it does have an impact.
Sites that rank higher in web searches will do better - more sales, more advertising revenue and hence more chance of survival.
Also, never click on the ads on sites that suck