This is a single tip that may be valuable to others, so I am sharing it
It is using a rather simple psychological trick, but I haven't seen it done anywhere yet, so...
Say, I have a site (ex.: nlp.snowcron.com), and there are couple of items I am selling, in this particular case, eBooks.
I have two engines to handle payments, one runs on top of PayPal, and another one runs using bitcoins (ex.: ecommerce.snowcron.com/order_hypnosis.htm).
Now, as you can see, there are "buy with PayPal" and "Buy cheaper with Bitcoins" links at the bottom of the last page, and there is a rather simple link to why is it cheaper with Bitcoins, and there is a link from that link
to what a Bitcoin is... And yes, the price, if you pay in Bitcoins, is significantly lower.
Which might - at least I hope so - trigger customers' interest to what the heck this Bitcoin is about.