I just went over the data for 2010 from our tree service sites.
Estimate requests from search engines:
15 - 35 a month. Interestingly clients in higher educated more affluent areas receive more requests. This factor is more important than actual population.
Facebook estimate requests:
1 all year. Although this is harder to quantify as I don't get to see traffic numbers and rely on my clients to give me the info.
In 2010 the number one response when asked how they found them was Google.
Social media definitely plays a roll in your overall internet marketing strategy my recommendations are to focus on traffic you can monetize. Facebook itself cannot monetize its traffic very well. Here is a quote from a recent article.
"Facebook can target ads to users based on their interests, but these users generally are not looking for or seeking out the advertisement at the time it is displayed. Just because a Facebook user is a Yankees fan doesn't mean that when he logs into Facebook he is interested in buying Yankees tickets. This is in direct contrast to Google, which targets ads to a user at the time they are seeking a given product or service."
Facebook's $70 Billion Valuation Is Way Too High
I guess no matter the medium as a business owner it is a good practice to focus on the things that are working for you presently with a keen eye on the horizon to see what might be coming next. Put some money aside to try out new marketing methods, new tools, new employees etc. If they work, use them more. If they don't, try something else.