When someone says "craig it" they mean "sell it on craig's list"
Bob: "I don't know what to do with this bike, I never ride it anymore."
Rob: "Why don't you just craig it and make some money off it?"
A friendship with someone you meet through the craigslist personals. Often is an email, chat or text-message based friendship that may or may not include meeting in person.
This craigship is over. I'm sick of you bugging me to have sex all the time! My ad was posted in the strictly platonic section, remember?