[JackC]

Yeah, this is something to avoid in general. There are some people who hear "girls" the same way you do, so "guys and girls" translates as "men and women." But there are also some people who hear "girls" to mean, well, girls, so this translates as "men and girls" and sounds very weird. As people get older (say, from 20-year-olds to 30-year-olds), the balance shifts more and more toward the latter and more and more of the women you talk to will think there is something wrong with you if you call them girls, even if you also call men guys.

So yeah -- seeing "girls" in a job ad would make me guess the workplace consisted mostly or solely of young men who weren't used to being around women, and I would only apply if that was what I was looking for. Whether you think that's a problem is up to you. (I happen to think there are good reasons that some women don't like being called girls, even in the "guys and girls" context, but it's sort of beside the point in terms of writing a job ad, right?)

[aestra]

Let me ask you a question (assuming you are a man)

Would you like to be called a boy?

Imagine being addressed like this (in a group of 90% women)

"Hello ladies and boys"

Wouldn't that feel insulting? And weird?

[theorique]

Speaking as a man, if I were in a mixed group and addressed in various ways:

guys and girls - OK. Very casual.

ladies and gentlemen - OK. Somewhat more formal.

men and women - Weird. Sounds stilted.

boys and girls - OK, depending on tone. Would work better with an ironic tone when addressed to adults. Would sound stupid if expressed in kindergarten teacher tone.

ladies and boys - seems a bit forced. Also, it makes me think of "ladyboys" (e.g. transgendered Thai prostitutes)

[telephonetemp]

Your analogy was helpful. Thanks.