Quite soon PCI compliance is going to be a "must have" for almost every online merchant who accepts credit card payments on their e-commerce web-sites.
Generally speaking, PCI applies to ALL organizations or merchants, regardless of size or number of transactions, that accepts, transmits or stores any cardholder data. If any customer of that organization ever pays the merchant directly using a credit card or debit card, then the PCI DSS requirements apply. Noncompliance may cause multi-thousand $$ fines and penalties to the merchant.
PCI Scan Compliancy enables merchants to achieve compliancy on up to 5 servers and also provides additional assurance for your customers by placing a high visibility trust indicator on your website.