With LinkTrust, there are two parts of s2s pixels. The first is at an offer level, where as Dan stated above, the offer owner needs to fire the s2s pixel (realy just a post back URL). But there is also the functionality with LinKTrust that if the advertiser fires a normal image or javascript pixel on the confirmation page, LinkTrust CAN fire your s2s pixel from the LinkTrust servers at the time of the conversion. Hope that makes sense. So if you're an affiliate who wants to uses a s2s pixel with LinkTrust regardless of what the offer owner uses, you can, just make sure to ask your affiliate manager to enable s2s pixels on that offer.