Challenge lobby free all you have to do is subscribe to my YouTube and post gamertag, that's it.
Anyone who posts this is just looking for subscribers.

Mw2 xp/challenge lobby message C3po saying Hello stranger, post gamertag and ill invite you.
Anyone who posts this is just spamming a friend.

Personally i would never ever pay for a lobby over xbox live because no matter hoe much proof someone has its not worth it. You wanna run the risk of getting scammed that's your choice, but i advise you its a bad idea, Hope this topic helped, i recently did a post similar to this but i didn't explain it thoroughly enough, Cheers, please thank this to keep the topic alive so others can read it, NOTE, I WILL NOT TOLERATE ANY SMSRTARSES. THIS IS AIMED AT THOSE WHO ARE STRUGGLING TO FIND A LEGIT LOBBY.