Product Page Optimization and User Acquisition

Has anyone encountered data distortion when conducting A/B test, for example 50/50 for an app page in App Store if I buy traffic in Facebook or for example UAC?

As far as I know the test distributes evenly to the entire audience, but some experts say that allegedly paid traffic violates the accuracy of the experiment, is this true?

Product Page Optimization and User Acquisition
 
 
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