The survey participants, called panelists are still a very small few (hundreds) representing millions and sometimes just one family can impact the outcome.
Regardless of how much “cheating” occurs and how small the sample size, nobody can debate that the meter system is an improved data collection method over diaries.
The immediate impacts of the conversion to PPMs in each market have been quite dramatic. First, the old currency, which was used for over 50 years, became null and void. Subscribers were no longer permitted to use the old diary numbers to quote rates. So, if one station had been the top performer forever, and their ratings suddenly plummeted, they were no longer allowed to mention their former status. What happened before no longer applies and the new numbers now rule.
The second impact was decompression of the numbers. More stations had their signals picked up and thrown into the mix and therefore, overall ratings went down. Some low-rated stations suddenly rocketed to the top. Actual listening was found to be less than what was reported by the diaries.