Marketers need to be more accountable than ever. If you have ever run a mix of television, radio, outdoor, print, online or social ads, you have probably been asked the question of what its impact was.
Each channel has a different measurement system, so to calculate the combined reach and frequency across all channels can be difficult. But don’t worry, here’s the formula to help!
Calculation for Combined Reach and Frequency Across Media Channels
Combined Reach = [(100 – (high reach))/100] x low reach + high reach
Combined Frequency = (GRP1 + GRP2)/combined reach
Now if you just read this and your head is spinning, here’s an example:
Example of Combined Reach and Frequency Across Media Channels
TV – 50% reach at a 4 frequency (200 GRPs)
Radio – 60% reach at a 5 frequency (300 GRPs)
Combined Reach = [(100 – 60)/100] x 50 + 60
= (40/100) x 50 + 60
= (.4 x 50) + 60
= 20 + 60
Combined Frequency = (200+300)/80
This campaign had a combined reach of 80% and an average frequency of 6.25.
Lastly, if you’re still confused at what a GRP is or how you’d go about calculating it for other media that doesn’t have reach and frequency per-se, here’s a helpful chart.
Chart Comparing Media Measurement by Channel
|Television||Nielsen Ratings||GRPs (gross rating points)||200 GRPs could mean 50% reach at a 4 frequency|
|Radio||Nielsen Audio Ratings||GRPs (gross rating points)||300 GRPs could mean 60% reach at a 5 frequency|
|Outdoor||TAB Out of Home Ratings||GRPs (gross rating points) & Weekly Impressions||One billboard gets 700,000 weekly impressions, meaning 100,000 people per day pass it|
|Verified Audited Circulation||Circulation and Readership||A circulation of 100,000 with a readership of 400,000 means that 100k people receive it and an average of four people read each printed copy|
|Online||3rd Party Ad Server (usually DoubleClick)||Impressions||1,000,000 impressions means an ad was displayed 1,000,000 times|
|Social||Specific Channel (Facebook, Twitter)||Reach/Frequency||Facebook ads shows 75% reach at a 2.3 frequency to target audience|
One caveat to all this is that although media buying is partly science it’s also partly understanding your audience and numbers. If you use the combined reach and frequency calculation and it’s giving you a really high number, please take in to account those of your target audience who may not consume media. Also remember that numbers are usually gathered using demographic information. For example, your TV ratings may be for adults 25-54 but your outdoor ratings may be for all vehicles.
Best of luck in measuring your ad effectiveness across different channels! If you need help please leave a comment or contact us and we will be happy to assist.