OK. One of the habits they have is clicking links. For example when they buy stuff online there is a link they click that directs them to the payment page where they enter their info and pay. Why not do the same with bitcoin and why complicate things with involving a centralized service and an Email?

Like this: pay me 0.1BTC
It is easy to use, it is readable and when you click it (assuming you have a bitcoin wallet installed that supports URL:bitcoin protocol) it will open it and fill in every information with a transaction ready to be signed.