Tipping from a server's point of view.
So I just got a gig as a server at a Vietnamese/Thai restaurant. Business is kind of slow, but it's a relatively new business. Since a server's income is based on tips, of course I get super happy when a customer tips 18% (I only do lunch shifts, so mostly lunch specials), but today, three grown men who ate around $40 US and sat around after finished with their foods and drinks, only tipped $3. That's not even 10%! I did my job as a server - refilled water bottles, cleared the plates and gave them space and not rushed them even after they were done. Of course I didn't say anything, but I was just dismayed by this (not that this is a first anyway). Any servers out there and how do you deal with these situations?