I know two friends that should join me for lunch. How does youguysshouldlunch work? Normally I'd give them a call or email and say "lunch is on me" or "I saw a

I know two friends that should join me for lunch. How does youguysshouldlunch work? Normally I'd give them a call or email and say "lunch is on me" or "I saw a new restaurant on X street, want to have lunch?".