by Ed Kohlerhttp://www.haystackinaneedle.com
While search engine advertising has been a great advertising medium for businesses capable of or interested in marketing their products and services to a national or international audience, the effectiveness of this type of advertising was limited for businesses interested in advertising to a local market until very recently.
For example, a realtor with a web site in Minneapolis is likely interested in advertising on search terms such as 'homes for sale' and 'sell my home.' The only problem was the realtor would have to advertise to everyone in the country who happened to type those terms into search engines. This was wasteful and ineffective because the vast majority of visitors clicking through to the site would not be qualified visitors since they lived outside the realtor's regional market.