A recent study by Imperva provides some interesting insights into the impact PCI Compliance is having in terms of the likelihood of a security breach.
http://blog.imperva.com/2011/04/pcis-impact-on-security-quantified.html
One of the more interesting highlights pointed out that over the past 24 months, 64% of PCI Compliant companies did NOT experience a breach, while only 38% of non-compliant companies were able to say the same!
Jeremy Simon, PCI QSA, CISSP, CISA
Practice Lead, PCI Compliance Services
HALOCK is headquartered in Schaumburg, IL, in the Chicago area and advises clients on information security and conducts PCI preparedness assessment, scoping, remediation, validation, and compliance maintenance services throughout the US.