So, I have been trying them both since last 3 months, couple of split testings. Run them both on Same blogs for almost same period. Although VigLinks is powered by google venture, has more programs in their network and probably more popular but i still find SkimLinks a way better choice when it comes to revenue generation. They both are good, both are easy to sign up but skimlink is fine for me. If you're confused about which network to go with, here is my honest opinion.
Does skimlinks allow placing their links into apps. I used share a sales, but they do not allow placing links into anything that can be downloaded.
FYI -- eBay changed its payment structure on Oct 1 --- http://www.ebaypartnernetworkblog.com/en/2013/09/new-pricing-to-launch-on-october-1st/ So keep in mind that the October results will be skewed