Coming In
When most Webmasters think about traffic, they focus on "getting" traffic, and their use of access stats tend to center on this. In other words, they want to know how many "hits" they got. At this stage of the game, most folks realize that "hits" are a pretty useless measure of site activity, since a page with nine images on it will generate 10 "hits" per viewer. This is the number one reason why so many newbies over-estimate the number of visitors their site receives.
Now that we're all on the same page, and looking at "visitors" rather than "hits," let's try to get a better grip on what we mean by "visitors." Ideally, we want to know how many "unique" "people" (as opposed to spiders, robots, hit bots, etc.) are visiting our sites, as well as how many repeat visitors we're getting.
But even more important than the simple number of folks knocking on our virtual door is HOW they found us. Decent stats applications will not only show you "referrers" (the site a visitor came from), but will also show you the search terms / phrases they used, if coming from a search engine. This information is an invaluable aid in determining the effectiveness of your SEO (Search Engine Optimization) strategy, as well as the productivity of any PPC (Pay Per Click) campaigns you may be running. Sure, most PPC programs will give you their version of that information, but having an independent metric is vital...
Another important reason to know how visitors found your site is to determine the effectiveness of your link trades, feeder sites, and other traffic sources. This allows you to focus your promotional energies where they'll do the most good.
Knowing WHERE people come from is also extremely important. At this point, I'm talking about the country (and even the city) they live in. For example, before I met her, my lovely wife Dawn's site enjoyed a lot of overseas (non-US) traffic, and made nearly as many video sales to Italian customers as to US ones. She still has a fair amount of Italian traffic today, and knowing that information makes a good case for having a professionally translated landing page (at the very least) to a geo-redirect / browser language sniffing script to welcome these surfers.
She's also quite popular in the Scandanavian countries and elsewhere, opening the possibility of offering original content specifically tailored to these markets, or offers through one or more of the better overseas operators. This information points out *where* you want to start focusing your "global" marketing efforts. For instance, with very little traffic currently coming from Japan, having a Japanese solution is far less important today than having one for our Italian traffic. Stats let us know this.
There are other important aspects to your incoming traffic that stats can tell you about. Browser type is one of them. Not a mere curiosity, knowing the percentage of non-IE users led us to modify certain pages and approaches on our site. For instance, using the Windows Media SDK (Software Development Kit) I was able to build a pretty slick custom video player. It didn't work in Netscape, however. In fact, lots of "cool" things don't work in Netscape, as well as a wide variety of older, and non-standard browsers...
Stats helped me make the decision to drop the custom player in favor of a more standard (and cross-browser) embedded player. Not as slick, but functional for more users. Without knowing the exact percentages, the decision of whether to change players, build a separate page for non-IE surfers, or to simply ignore the lack of video functionality for certain surfers, would have been based on guesswork.
Similarly, knowing the typical screen size (resolution) and color-depth of your users can be used to influence design choices, as can knowing the number of users who have JavaScript and cookies enabled.
Finally, while I've focused on discussing incoming traffic in terms of "people," there are also non-human agents (the aforementioned spiders, robots, hit bots, etc.) hitting your site, and understanding them is also very important. Knowing which bots are visiting can help tailor your "robots.txt" file, and can also provide clues into not only abusive behavior, but profitable goings-on as well.
For example, knowing that Yahoo! is hitting your site already could save you a $600 adult submission fee, while knowing that Google or any other SE is already on the prowl can keep you from submitting there, saving you time and energy. Likewise, seeing the spider from a search engine that you have already submitted (or re-submitted) to will let you know when to monitor that engine for your listing status.
While knowing where your traffic comes from, how these folks found your site (and what they're looking for when they get there) is vitally important, it's not your only consideration... Stay tuned for much more!