Anything that increases privacy (VPN, etc) and increases profits (Bitcoin wallets and checkout services.) and that you can pay for items in Bitcoins, is good.

My market is looking for more privacy and better ways of doing business and they love paying with Bitcoins.

Any niche for the modern high net worth international businessperson is welcome. But the payment method must be bitcoins and I want a cut of the action. (a small amount, I am not greedy)

Since I know this market all I have to do is talk about the product or service and put my affiliate link up.