You can't have a brain in your head and think posting on slickdeals is a good idea. That site has so much traffic, even big retailers like dicks, HD, Lowes, admazon, etc. can be wiped out of a product in less than an hour (if the deal is enough).
But what if they do have a brain...
While I'm certain that majority of the people posting stuff on SD are in it for the rep. points, I suspect many are from people that have an actual stake in the site's success.
If I owned SD, I'd monitor any private/public forums I could join for deals that I could re-post on my site. I'd also pay people to do the same bc I'd be too busy making it rain and chowing down on wings during the lunch buffet at the local **********. Payouts would be either based on page views or a percentage of any affiliate revenue generated from their posting.