What does an advertiser buy? Is it share of market? Not exactly.
When an advertiser places an ad in a b2b magazine, web product, or broadcast media, he or she is buying an opportunity to increase the share of mind that they have with potential buyers of their product or service. An increase in their share of market could and should result from an increase in share of mind but much more is involved.
In order to increase share of market, a marketer of products or services must have the right price, distribution, and product features. With the right ad program, the latter factors have a chance to work. As more buyers know about the existence of a product/company, their examination of the product, price, and availability increases and this leads to increased market share.
I have been in the advertising business for many years. All too often, new advertisers have told me that they will try some ads and if they get the return that they need, they will continue with the ad program. How do you measure success of an ad program?
When I first started in this business, a print ad in a trade magazine was expected to generate bingo card inquiries from about .1% of the circulation. With the introduction over the years of toll-free numbers, fax machines, e-mail, and internet, those numbers have obviously shrunken. Even when it was .1%, that was not a good indicator of success.
The only way to measure success of an advertising campaign is to determine that more prospective buyers knew about the product/service being advertised after the campaign than before. Or, that more prospective buyers would consider buying the product after the campaign than before. Or, that more prospective buyers of the advertised product/service were reminded of it and thus had higher potential of buying.
These are all measures of share of mind. Increasing share of mind is what advertising will do!