It's not surprising that many webmasters' first forays into conversion rate optimisation run into some problems. CRO is a fresh-minted field, and not an easy one to learn on the fly – so much so that even well-planned, well-built, and well-run sites can easily be scuppered by some less-obvious rookie mistakes.
1. Broken Search Functionality
Try this quick experiment: head to a small-scale site, and try their built-in web search. I'm going to go ahead and assume it's a “results powered by Google” deal, and is, for all intents and purposes, functionally useless. Now go search for something on Amazon. See the difference?
A good search bar is key to increasing conversion rates, as it helps immediately connect customers to their most sought-after information or services. Bad ones, on the other hand, actively drive people away. When working on your own site, implement auto-suggest, make intelligent use of categories and other search-friendly information architecture, and for goodness' sake, test, test, and test some more.
2. Ugly Product Photography and Videography
It doesn't matter how good an SEO you are if you're not impressing customers. Ugly (or too-large, slow-loading) photos are a cardinal sin of small-to-mid size E-commerce sites. We get it, photographers are expensive, and your iPad has a great camera, but don't fool yourself, this is one area where it pays to go professional.
3. Poor Use of Personalisation
“Build it and they will come” might work for ballfields and restaurants, but it sure as heck won't for websites. It's completely possible to create a beautiful page and see zero returns, all because you've taken aim at the wrong demographic.
Working with your desired end users in mind drives facets of design that range from color choice to cart reminders. Before dumping time and effort into CRO, decide who exactly you're trying to convert.
4. Bad or Missing Meta-Information
Don't let meta tags fall by the wayside. Most modern SEO's realise how valuable these snippets are for UX purposes, but some business owners and webmasters still haven't gotten the memo. Just because search engines ignore them doesn't mean that customers will; keep your meta info sharp and under 160 characters.
5. Make Conversions Easy
This one's obvious, but good lord is it important. If your final conversion is a purchase, then you need to have multiple payment options. If it's a newsletter signup, don't force visitors to give you their phone number. If a feature or requirement drives you nuts, it'll probably have a similar effect on customers.