Note that the advice here has been for buyers using eCommerce. As this forum and board is intended for those hosting a site, it would be far more relevant and useful to discuss what things a store owner should do (security-wise) to attract buyers. Other than using https: instead of http:, and using a well-respected brand of payment handler, what can be done for security? The other advice, such as not making purchases in public (I presume to avoid having someone looking over your shoulder) and not using public (unencrypted) WiFi (though https: will help here) is good for your buyers, but here we're interested in what you can do as the store owner to increase security for your customers.
Please cease further discussion of anything involving customer security that is out of the control of the store owner.