Marketing : You would like to test whether a social media ad you created has a significant impact on the purchase rate of your new product (versus no ad). Your analyst decides to run an A/B test on Facebook. However, one concern you have is that Facebook is highly likely to show consumers in the control group an ad for a competitor.

As a result, your analyst modified the experiment and introduced a Red Cross public service announcement targeted only at the control group. You now have the results, which compare the purchase rate between the treatment group (who are assigned to see the ad) with the control group (who are assigned to see the Red Cross PSA). After reviewing the A/B test, do you think the results are biased? Please explain why or why not.