The excerpt and link below is to a white paper from Cactus Sky Communications. The bottom line of the article is that people (especially young people) use “search” as their primary method of shopping. Social media is very popular but not as important for shopping. The other big deal is that people are more likely to click on the “organic” results, that is the actual search results not the paid results, than they are to click on a paid adword result. Finally Google Adwords have been around long enough that many people use them and in some industries the market is saturated and advertizers are seeing less of a return on Google Adwords. I do not believe this is the case in dentistry but do not have any research to back that up.
…organic results receive 2/3rds of all activity on the search engine results page (SERP). The first page is also prime real estate because over 95% of searchers never click to the second page of results.