Do security messages increase sales?

A client wrote an email that reads "....I've been reading a bunch of articles and blogs on ecommerce carts and one of the trends I noticed was that customers are more likely to purchase something from your site when they "feel" secure using it. What sort of messages/images can we display/use to create this "feeling" that our site is secure?"

Providing reassurances to the customer through the checkout process does lead to less cart abandonment and encourages conversions.

So what kind of messages make you feel "safe". It's not just one thing. Trust arises out of lots of small trust-producing features.

• Start with your full postal address and telephone number of your company.  Put your phone number large on the page.
• Be up front about all charges (delivery charges, handling, etc).
• Offer clear signs of server security, SSL locks, security icons, etc. (The McAfee/Hacker Safe logo reported increases sales by 14%).
• Use Opt-in options rather than opt out schemes (nobody likes to feel they are being scammed into signing up for a newsletter)
• Include links to privacy policy, security policy, etc.
• Build trust by ensuring that the entire checkout is a smooth process and error free (nothing destroys trust like a broken process).

So what is the perfect assurance message? No one message is going to work for everyone. Start with some of the basics, and then use Google Website Optimizer to test it over time.