I'll Go if ____ Goes

Often, I offer my inclusion for an event stipulated on someone else going. I'll Go if ____ Goes.

One reason is that I know that ____ isn't going to go and it's an indirect method of saying no. This is probably not the best method of communication though.

Another reason, probably often than the first, is that I think it would be more fun if ____ were to come. Putting the stipulation may encourage ____ to join if ____ needed any more motivation.

Sometimes, it's more encouragement for me to go as well.

Do you ever use this tactic?