Online support via Skype/MSN etc surely makes the buyer or "soon-buyer" feel safer, I've been providing a service for a long time now, and I Always give them my Skype id/msn (or whatever chat system they have), even before they buy my service.
Why? I don't promote the service now days, and I keep getting clients, because I offered support before the buyer buys my service, and they simply liked it, and they recommend it to many people, and if you have skype or w/e, your buyers can just tell their friends your skype id (happens a lot! Believe me!).
This goes for WSO, answering questions via Skype helps too! And helping them out after they buy your ebook is great, because these buyers, if they love your product, and you offering support via Skype/MSN is a great thing, they'll go for your next product, but I'm not saying that if you don't offer support they won't buy your next product, but more people will buy it.
Has anyone done something similar like this before? If so, I'm sure you can tell us your experience.
Just my 1 cent for more income.