Constantly.

Your site, no matter how well it was originally designed or re-designed, will perpetually need updates, upgrades, and revisions. That is just the nature of the game. It is possible to overdo it, but as long as you’re not making changes several times a week you are doing fine. If you don’t even look at, or consider making updates once a month, it’s time to step up your game. I guarantee you are losing money every day if you haven’t made any changes to your site in the last 3 months.

It’s important to not just make changes for the sake of it. Analyze your site’s performance, find the weak spots and make them stronger. The word “SALE” is not always necessary. A good site design with strong branding may inspire confidence in your customers, but if they can’t find what they are looking for, you’ve lost them. If this is the case, usability is often the suspect, but not always the culprit.

Your customers may not be seeing what is relevant to them when they first come to the site. A good site could even give the wrong impression. You need to find out what your customers are looking for, which can be aided by your his analytics program. Market your store to people who will find it relevant.

If you put an ad out for “Simpsons” T-shirts, and people come to your homepage and see “Batman” shirts, they will immediately hit the back button. The site was not relevant to them. This can increase traffic without increasing sales, which will cause conversion rates to drop even if sales do not.