Here at Hubspot, we found that, on average, marketers redesign their websites every 18 to 24 months. Which means, even if you just cut the ribbon on your brand new parallax scrolling homepage, odds are you're going to give that homepage a funny look and declare, "It's time for a redo," in no time at all. It's exhausting when you think about it, but the frequency also makes sense.

Think about how much business changes in 18 to 24 months. Think of how much the world changes in 18 to 24 months. Just 24 months ago, mobile represented about 10 percent of all internet traffic. Today, not only has that number jumped to 25 percent of all Web traffic, but Google is rolling out ranking changes that prioritize mobile optimized websites on search engine result pages. Buyers have changed, too. Today's website visitor expects a different experience than those of the past.

The risk in frequent redesigns however is that they become willy-nilly (that's a technical term) and lack strategic end-goals. Whether you work with an agency or revamp the site in-house, it's crucial to make your website a revenue driving channel, not just another pretty homepage.

Do your research

Before investing resources into revamping your site, map out what you want to change and why. Be careful of redesigns that are sparked by "I just want it to look more modern" or similar vanity goals. A website should work better after a redesign in addition to looking better. Before doing anything, open up your analytics and record your starting position or benchmark for visits, search rank, conversion rate, and other key website metrics. Create a goal and a strategy for how each of these metrics should change as a result of your redesign. Having clear growth goals will give you an objective framework by which to measure the effectiveness of the redesign and a process for future improvements moving forward.

Get personal

Another sweeping change in buyer behavior over the last two years is the growing expectation of a personalized experience. According to Janrain, 74 percent of online consumers get frustrated with websites when content appears that has nothing to do with their interests. Groomed by Amazon, Netflix, and other adaptive websites, visitors seek out content that is specific and relevant to them. In fact, a 2013 Monetate/Econsultancy Study found that in-house marketers who are personalizing their Web experiences see on average a 19 percent uplift in sales.

Adding a personalization engine and strategy to your next redesign can help you address weak conversion rates. Say you run a sports-equipment business and a visitor recently purchased a basketball on your website. If they visit your site again in a few weeks and see a promotion for the same basketball, they'll probably ignore it. Instead, you could display related products, like a ball pump, to that specific visitor. The companies that cut through marketing clutter today aren't the ones with the flashiest ads but the ones creating a unique and personalized experience.

Be responsive

As noted above, buyers are increasingly using smartphones and tablets to find information online, and companies that don't optimize their website from screen to screen are losing out. According to a study conducted by Google, 79 percent of users who don't like what they find on a mobile site will go look for the information they need on another site. This shouldn't be a surprise; if you walked into a store that was messy, unorganized, and had unhelpful salespeople, you'd probably leave immediately to shop somewhere else that was easier to navigate. Use responsive design to create a site that adapts to fit a variety of screen sizes and be sure to incorporate behavior patterns of mobile users into your redesign strategy.

Focus on function

Visitors land on your website for a purpose. It's your job to make it seamless for them to achieve it. The first step in this is load time. While load time may not be as exciting as a good visual design, it's a huge factor for your potential customers. Forty percent of people will abandon a Web page if it takes more than three seconds to load. Free tools like Pingdom and Yottaa's Website Test will help you get a sense of how quickly your website loads.

As part of your redesign, look to lighten the load on your site and ensure it appears properly on a variety of devices and browsers. In addition to load time, look at the structure of your website. Is it easy to navigate? Is there a clear route from research to purchase? Mobile visitors in particular are action-oriented and need a clear route between point A and B. Use this redesign as a chance to make your site easier for visitors to move around throughout the sales cycle, instead of making them jump through hoops to become a customer.

Visual design choices are often the first to cross your mind (or your boss's mind) when it comes to website redesigns, and for good reason: The visual experience of a website is important. In addition to that strategy, however, make sure your next website redesign incorporates functional improvements that reflect the way today's viewers use your site. These improvements may not be as noticeable as new images or branding, but they can be the difference between a good-looking website and a high-impact one.