I received an email invitation to download the Media Insiders Panel iPhone app on December 27th, 2012. I downloaded the app to my phone the same day after I saw that I could get a $5 Tango card for using the app for at least 20 days a month. It was to run in the background while I used my phone and went about my business. Since the app was supposed to have no impact on my phone's battery life and I'd get something for using it, why not?
I kept the app going whenever my phone was on (read: almost all of the time), even after I got another email from Media Insiders Panel on January 22. The email announced that they would no longer support the iPhone app and were moving on to Android, iPod, and iPad devices. This didn't really seem to be too much of an issue because I'd had the app going for over 20 days in January. Still, something in my gut told me to email "support" and confirm that I'd still get January's Tango card. So I emailed on January 23rd asking if it would impact my reward to uninstall the app before February.
On January 25th, I received a response from John in "support" stating that I wasn't getting my Tango card because they only received eight days worth of data from my phone. This seemed a bit impossible because my phone is only briefly off to charge after the battery dies, and I use data and wifi to access my apps. When I wrote that to John, he again said there were only eight days of data and that I hadn't responded to the emails they send after five days of inactivity.
Well, how can I respond to an email I never got? I checked my email (including the spam and trash folders) and never saw any reason to think my data didn't get sent. Since my phone was online and powered, I'm sure there was plenty of information sent. Especially since I never got the "we haven't heard from you emails"--and I check my email multiple times a day.
This seems like a lot of trouble to back out of paying for what they got. Don't let them spy on you for free. Don't download the Media Insiders Panel app to your device.