In many respects marketing by word of mouth can be said to be the “hidden statistic” for all programs, as it’s well near impossible to actually gauge the effectiveness of marketing done this way. Saying that, however, it should be noted that almost every product in this increasingly digital age has, at one time or another, relied on this method of marketing to increase public and corporate awareness of product or service availability.

A recent study proved that two thirds of online marketing will be done on this basis alone in the coming year, which when coupled with the advent of Web 2.0.0 social networking and social marketing sites point towards promoting your product by word of mouth may be both more cost effective, and have an increasingly better ROI than more “traditional” online advertising media.

Consider any of the current online social networking site's business model. There has yet to be a successful site of this type that charges for any sort of membership, relying instead as they do on ad generated income to fuel their corporate engines. While there is not in a real sense a metric that can be used to measure the effectiveness of marketing by word of mouth, it should be noted that there is one method of knowing if your campaign is succeeding – sales.

A company or client should know from their output volume exactly what the difference between before a campaign, during a campaign and after it’s stopped. This gives businesses a highly measurable statistic to show effectiveness of this methodology. It is true that not all businesses need or desire this form of sales technique, but is also through that not one business turns away prospects garnered from the by word of mouth method either.

Whatever your business, a study completed by Hill and Knowlton in February of this year showed that decision makers are more influenced by personal experience’s (58%), with recommendations and industry reports tied at 51%. Coming in third was direct marketing at 21% with internet advertising at 17%. These figures reflect the buying habits of decision makers, but a housewife in Washington deciding to buy her car insurance is the key decision maker in that case, and suggesting that her friend Tammy also deal with this company, will ultimately have more weight on Tammy's future decision than a TV or print advertisement any day.

In essence, this statistic can be shown to reflect into any industry, any segment or niche, if every purchaser is considered the key decision maker. This makes the resurgence of the world’s oldest sales tool a given – so get talking or tweeting, but tell everyone!