In addition to Counting Clips, many PR people calculate Media Impressions (the number of people who may have seen an article, heard something on the radio or in a podcast, watched something on television, or read something on a web page or blog).
This is a navigational metric. That means, it can help you navigate toward higher profitability but it can't help you measure profitability. For more details, see here.
For measuring profitability, you need evaluative metrics.
Use each news outlet's circulation number (or listenership, viewership, audience, or number of subscribers or members).
For example, if an article about your company, product or service appears in a monthly magazine that has 1.8 million readers, then 1.8 million people may have seen the article.
This calculation assumes that 100 percent of the readers saw the article, but that assumption is never accurate.
For example, a subscriber may have skipped that article, or might have been on vacation and missed the whole issue. The same goes for radio and television – someone might have been out of the room when "your" program was on.
Some PR people also factor in a "pass-along" rate. The pass-along rate is the number of people who see each issue, including the subscriber/purchaser and every other person his copy is passed to before it is discarded.
Estimates of pass-along rates run as high as 5 (five readers per copy).
So, a magazine that has a circulation of 500,000 and that claims a pass-along rate of 5 would have a presumed total readership of 2.5 million.
Often a magazine will state these numbers on its rate card. However, many PR people are skeptical of pass-along rates; in their reports to management, they conservatively use only the circulation numbers.
To calculate total Media Impressions for one month, you record the specific outlet's circulation number or total readership number for each clip that appeared during that month. This gives you an estimate of how many readers, listeners, viewers or surfers may have seen or heard your coverage that month.
Like Clip Counting, it's better than nothing. All other things being equal, and assuming positive stories, it's better to have more impressions than fewer. Calculating Impressions is more useful than just Counting Clips, because the calculation includes the circulation of each outlet.
For example, if you merely count clips, an article in a suburban weekly newspaper appears to be as important as an article in The Wall Street Journal; but if you calculate Media Impressions, the Journal piece would count for much more (as it should, unless your business is strictly local).
Calculating Impressions is also an easy way to summarize your clips. It gives you some numbers to show to your management.
This technique has the same kinds of weaknesses as Clip Counting, because the numbers ignore article length and placement, appropriateness to the target audience, and message content. And, of course, the numbers do not measure audience behavior or your profitability.