Skimlinks is actually a service we offer to publishers who don't have the capacity or capability to apply affiliate marketing to their own sites. We provide a simple solution so they can focus on creating quality content about your products and services. Consequently, they have the final say over which merchants they promote.
You can find a more thorough explanation here: http://skimlinks.com/merchant-overview
The easiest way of working with us is to ensure that we appear as an active affiliate within your preferred affiliate network program. As far as promoting a brand goes, the best thing to do is to push offers through your usual network channels. We monitor these and inform relevant publishers accordingly.