Tips for Running PSA (Test and Control) Campaigns
Published: December 12, 2013
Author: Judy Morimoto
I recently did a blog post on the value of View through Conversions (VTC), in which I discussed the effectiveness of PSA tests in determining the true value of VTC attribution. For those new to PSA (test and control) testing, here’s how it works: the advertiser pays for display campaigns for selected non-profit organizations (we recommend the American Red Cross!) to determine the lift in performance between users who were exposed to your ads and those who were not. The advertiser gets data, the non-profit gets free advertising, and everyone wins! (Great holiday story, no?)
Here are a few things to keep in mind when you’re setting up your tests.
Try to isolate your audience from external marketing influences as much as possible: Since the purpose of a PSA test is, as mentioned, to determine the lift in performance between users who were exposed to your advertising (test) and those who were not (control), isolating your audience from other external influences is key. Running TV, radio, or direct mail campaigns, etc. alongside with your PSA test will most likely dilute your control group because they are being exposed to your client’s advertisements through other verticals. This may inflate your control group’s performance and therefore skew your overall results.
Seasonality: Every advertiser has their high and low seasons; try not to run your test during either one of these times. Test group performance will most likely be affected either way, and accurate results will be hard to achieve.
Testing takes time: Normally, I would recommend at least 2-3 months for this type of test. Most lookback windows (the time from last exposure that a user has to convert) are normally 30 days, and you’ll need at least this much time to clear your cookie pool from users who have been exposed to ads running before the start of the PSA test. Normal percentage split is 90/10 (test/control).
Once the results come back, you’ll have a data-driven story to tell regarding view-through conversions and their value within a holistic advertising campaign…and maybe you’ll have helped spark a little extra goodwill in the process!