E-commerce web usability is a game of probability, not possibility. If you try to allocate the same weight to elements that attract product-oriented purchasers as you do comparison shoppers and casual browsers, your site will fail all of them. You need to review which groups of users you have the most of, then allocate your site's real estate to serve their needs. Web analytics is your friend here. Once you spot the patterns and know what kind of primary and secondary visitor groups you have, it's time to roll up your sleeves and get to work prioritizing changes to your website.
Designed to Convert
You've probably heard this one before: When you're trying to get a visitor to your site, you should be screaming for attention. While they're on your site, you should quietly let them shop. The shouting stops at the entrance. Nobody wants a bazaar while browsing. At least, in theory, nobody wants a bazaar.
Technology is your friend. That's what marketers say after they employ a largely tech-driven tactic that provides some lift. Unfortunately, that's rarely the end of the story. Often, things that look simple — e.g., implementing pop-ups to capture email addresses for remarketing or enabling promo codes — can have unintended consequences. If you don't think through the usability impact or downstream conversion effect, technology-driven improvements will often cause tough-to-diagnose pains down the line.
Tablets are, in many ways, a nightmare for a lot of retailers. Don't get me wrong, smartphones ultimately made the expectations tougher for everyone. However, optimizing for a four-inch screen is ultimately very different from optimizing for 19 inches and up. Say what you will about how difficult it is to create a good smartphone experience, but the tasks for mobile phones are often different enough from desktops that the changes you'll often need to make are obvious.
Some websites are so broken that tweaks really aren't the best approach. Yes, you can split test your way into some minor gains, but if most of your users can't GET to your product page, or at least not the right one, then boosting conversions on product pages by single-digit percentages isn't going to make anyone very happy.
Local was already in play before the iPhone changed the online marketing game in 2007, but the mobile shift has raised business capabilities and, more importantly, visitor expectations. Some of the things you need to learn to cope will be brutal, especially if you have limited resources, but it's time to start allocating some of that budget to local optimization now.