I recall an older study that found that many regular end users can’t differentiate between Google search list results and paid or sponsored advertising links. Some think sponsored mean ‘better’ or ‘recommended’. I find very very few friends who are aware of the issue of content spam. Many proudly declare how they check their prescriptions and buy cars through good online research.
Therefore I think it’s incumbent on search, research, and information literacy trainers to know how adwords work. Here’s a simple overview.