Shouldn't the starting point be:
What PROBLEM is it that we should be addressing in terms of the RESULTS we need to create/
Is a particular solution being considered (in this case, Adwords) the best solution, and/or how does it provide value (furthering our desired result) over and above unpaid methods)?
Does our "solution" actually reflect how "regular citizens" behave in terms of finding information?
The danger that I see reflected in this discussion is the notion that we think of the capabilities of technologies, which are cool, and jump in without really doing the analytical thinking that makes them potentially effective. I see this all the time with social media and tech. solutions -- that they don't reflect how people actually behave, but are more reflective of the notion that technology, in and of itself, is "good", so we should use it.