Do not just say hi but hand out your card. Something they can take with themselves and maybe later call you and presto, some new business.
Or, and this is a big or, a number or address a person can call or write to later, trying to sell you something.
So forget it, not that it’s ever been tried.
Look. Just say hi and let go at that. With a smile, of course.
It’s what I do at the other greeting time, the handclasp of peace later in the mass, when I sometimes do not clasp a hand but wave, and then not to whole rest of church, of course . . . .