Dear Jeff,

My partner and I constantly argue over two web metrics. He feels we want more repeat visitors while I feel the average time spent on our site is more important. Settle the argument, please.

-- Name withheld by request

You're both right.

We'll start with some basics. Repeat Visitor Ratio (RVR) measures the percentage of visitors who return to your site after an initial visit during some specific time period. If you got 4,000 visitors this month and 800 were repeat visitors, 800/4,000 = 20 percent.

RVR is one way to determine whether you are successfully engaging visitors.  Say you're analyzing your blog.  You work hard to bring new visitors to your site, even running some PPC ads to generate traffic.

New visitors are fine, but repeat visitors are great since once you "have" a new reader you don't have to spend time and money attracting that reader--your content is sufficient.  So the higher your RVR the better your website must be at engaging the average new visitor.

If you run an information-based website you depend on repeat visitors.  Even if your ultimate goal is to sell a product or service, you're much more likely to sell to visitors who come back time after time. The old cliché, "A person has to see an ad seven times before they'll buy," is actually based on data.

You can get more total visitors by advertising more, but what if you find ways to raise your RVR?  Your marketing becomes more efficient because you're getting more bang for your advertising bucks.  (Or you could decide to lower your advertising spending because you are able to "convert" a higher percentage of visitors even if the total number of visitors is reduced.)

How do you improve your RVR? Better target your marketing, provide great content, ensure site navigation is streamlined and intuitive, and constantly create new content to keep the site fresh and relevant.

Now for the time visitors spend on site. Average Session Length (ASL) measures the average amount of time a visitor spends on your site or on a particular page. If you got 4,000 visitors this month and they spent a total of 29 hours on your site, the average session length was 26.1 seconds.

Sound like the average visitor doesn't stay long?  Don't feel bad; in some industries the average visitor stays a lot less long.  On the other hand, major online shopping sites average session lengths in minutes, not seconds.  It all depends on the nature of your site and your industry.

You can also use ASL to evaluate the success of changes you make to a particular process.  Say you streamline your checkout process; if sales remain steady or (hopefully increase) while ASL decreases that should indicate transactions are taking place more quickly, which is a good thing for all concerned. In that case, reducing ASL on specific pages may be the goal. The quicker you can get me checked out the less likely I am to abandon my shopping cart.

Keep in mind a relatively long ASL could indicate visitors engage with your content and want to stay, or it could mean they are struggling to understand your navigation scheme or to find meaningful content.

In general, though, a longer ASL means you're successfully engaging your visitors.

So who is right? Both of you are.

RVR is a great measure of engagement, but never forget that while you want to increase the percentage of repeat visitors, you also want to increase the total number of visitors--otherwise you'll start preaching to the same choir.

ASL is also a great measure of engagement as long as visitors stick around because they love your content and not because they can't find what they want or keep getting lost in a confusing site layout.

So if it was me, I'd try to improve both metrics.

More financial and performance measurement articles: