Word of the day: leave-behinds

So I was on a course recently and one of the speakers had prepared handouts for everyone.

Except he didn't hand them out - he left them behind. And he didn't call them handouts, he called them 'leave-behinds'.

I'd never come across this word before (although it makes sense). Googling 'leave-behinds' throws up a few definitions, including:

• A part or sampling of a portfolio that is left with a potential employer or exhibitor after a meeting or interview (Wikia)

• Things other than your resume that can be left behind with potential employers (About.com)

• Something you leave behind, compelling your audience to take a closer look at who you are and what you offer (Go-to-Market Strategies)

• A creative reminder of your particular style. Even if you don't get the job but your leave-behind is considered a "keeper," the designer or creative director will hang onto it in case they need a freelancer in the future (The Graphic Designer's Guide to Better Business Writing)

So this word seems to be most often used in the contexts of design and recruitment (and especially design recruitment). Perhaps these are fields in which the speaker had experience?