agreed, i see a large number of servers intermingling. it makes sense, they share similar experiences and have mutual familiarity. if the servers at the same restaurant aren't hooking up, they are frequently dating someone else from another restaurant. this is because turnover is frequently high at restaurants, and it's not uncommon for servers to bounce around through different local eateries within a year or so of employment. all in all, same job description, same family.
two of my longer term girlfriends, including the one i'd dating now, i met at the restaurant where i was working.
i have long wondered this prior to starting serving, as i've noticed a large proportion of waitresses being hot. questions were:
1) who is dating these girls?
2) do i have a chance picking one up?
so the answer is, likely the male servers are dating the female servers. and no, customers who leave their name/phone number/business card to try to pick up a date will never get called back.
the waitresses at my previous restaurant had a very love/hate relationship with particular gentlemen. they'd have guys who came in and tipped well and made lots of small talk (in hopes of impressing the waitress). and while the waitresses on some level, liked the attention and certainly the money, they were tired of being ogled and avoided those guys as much as reasonably possible (while still providing food service).