This trick requires a Wii. Once the "Mingle" option is available in your player menu, you will be able to accumulate MPP, or Mingle PP. It is rare to find someone actually broadcasting their DS. To get around this and still get MPP (without the random alien appearances), you can get Civvies points through your Wii. Use the following steps.

A. Make sure your Wii is connected to the Internet.
B. Make sure your Wii has the Nintendo channel (can be downloaded from the Shopping channel for free).
C. Open the Nintendo channel of your Wii. Select "To the Video List", then "Find Titles for You", and finally "DS Download Service".
D. Select any demo to download. Your screen should have a "Preparing" message on screen. Wait until it changes to "Transmitting".
E. Enter Mingle mode on your DS and wait a few moments to receive a Civvie. Each Civvie gives you 20 MPP.
F. Note: This next step saves data; make sure you have only pins you want to receiving MPP equipped. Exit and re-enter to receiving 20 more MPP.