If a CubeCart feature seems to fire erratically or not at all, this is almost certainly why. Setting up a real cron entry is the single most useful thing most stores are missing.
Categories and products can now be restricted to specific customer groups, with bulk group pricing tools. Trade and retail from one store, without a plugin.
Most speed advice is a checklist with no order to it. This is the sequence we actually work in, why the server comes before the images, and the optimisations that are not worth your time.
Nearly every CubeCart vulnerability fixed this year requires an existing admin session. Two-factor authentication is the control that breaks that chain, and it takes five minutes per account.
CubeCart now includes a genuine 3D bin packer that works out which boxes an order actually needs, rather than quoting shipping on total weight alone.
Tax rounding, coupon tax and gift certificate handling were rewritten across four releases. Some of your figures have legitimately changed, and you need to know which.
An XML sitemap hands search engines a list of your pages. It takes minutes to set up, it is easy to break silently, and on a shop with a deep catalogue it is the difference between pages being found and ignored.
Flat rates subsidise heavy orders and overcharge light ones. All In One Shipping calculates from weight, subtotal and item count, with postcode zones capable enough to handle the Scottish Highlands properly.
Around 70 percent of baskets are abandoned. CubeCart can email those shoppers, but the feature is off by default and, before 6.7.6, could email customers who had already paid.
CubeCart 6.6.0 shipped around ninety changes in a single release: a REST API, two factor authentication, abandoned cart recovery, 3D box packing, a rewritten tax engine and a full security audit. Everything that changed, and why you should not run 6.6.0 itself.