Earlier quoted context omitted.
It should also mean though that cross-posting to other sites like Kijiji (very common) could result in having take-down notices sent for your ad (- since it's an exclusive license you're granting them). [IANAL]
No it isn't. The information that is used to build the ad remains open to be used wherever and whenever the poster wants. I believe this storm is caused by third parties leeching off their ads and not users posting the ad in multiple places. Let's not get too dramatic about it.
"BRAND NEW CONDO 1BA 1Br wood floors!!!! sends us an email. $1200/mo!!"
If you take that same ad and post it on Craigslist and another ad service, the license with Craigslist gives them exclusive rights to the ad--if I'm reading this right it means they can then tell the 2nd ad service to take the content down since CL has the exclusive license. I'm not saying CL will do this, just that having that kind of license up front opens the door to such a scenario.