To my knowledge, both participants have to send a match invite via lookout. If you chose minimum limit of participants to be 2, then your friend also has to. As far as I can tell from the few times I've done it, the automatic match finder still has some bugs. During potco it'd automatically send it to every player and first to accept would face the sender. However now someone else has to personally send a lookout also. "Of course this'll be fixed in beta or live I'm sure." I hope this helps explain things/gives a general idea as to how it works.