Darren Guarnaccia (pictured below) brings a taste of what you might be missing.

It’s safe to say everyone loves a bargain . . . and what better bargain than to get something invaluable for free.

Back in 2005, Google shocked the world when it launched its new web analytics service for free. A bold move to be sure, but it made a lot of sense for Google’s business. Google wanted customers to better understand their website traffic and made it very convenient to tie that traffic to advertising results using the Google advertising network.

Over the years, Google has steadily improved this free service, expanding its capabilities to include new features, such as customised reporting, advanced segmentation and API based access to its data repository.

But has it really kept up with the market’s requirements?

While Google Analytics does offer valuable reporting on overall traffic statistics and tracking for your website, it suffers from issues common to many of the ‘page tag’ based hosted solutions. It’s also a victim of its own success and design.

There are several things to be aware of when considering free services like Google Analytics. It’s important to know not only what these services will tell you, but what they cannot as well.

The first thing to understand about page tagging solutions like Google Analytics is that they rely on three things: Javascript, first party cookies and third party images. Tools like Google Analytics depend on being able to trigger an image on its servers to transmit information back. Increasingly, however, this is being blocked by web browsers or ad filtering technologies by default. Additionally, more web browsers and antispyware plug-ins are explicitly blocking analytics cookies (Google, Webtrends, Omniture, etc). The net effect is that you could be missing more and more traffic in your reports from Google Analytics.

Is this statistically significant? At an aggregate level, 10-20 per cent isn’t too big a problem, but things are changing in the web world. As today’s websites shift away from being passive marketing sites towards becoming active marketing and sales platforms, the devil is in the details.

The other thing to consider is that services such as Google Analytics, by default, don’t understand how your site is structured. These types of services see your website as a bunch of separate web addresses or URLs. There are going to be times when you’d like to understand traffic to your homepage across all languages and that’s a tricky, time consuming thing to do. Also. if not kept up, it can lead to inconsistent or incorrect results over time.

To help with this, most content management solutions have a tool that lets you map all the related addresses to each other, such as pages across languages, or where one page has multiple domain names or vanity URLs. Many of the more modern technologies can do this mapping automatically.

Today’s marketers and site managers are starting to delve into the sorts of details that services like Google can’t or won’t keep. Part of the issue is down to the huge quantities of data involved. Google Analytics can’t possibly record and store the intimate details or each and every session on every single site it handles for years and years. The sheer volume of data would be unmanageable. As it stands today, Google will only keep 13 months of data for you. If you want more, you need to download, store and manage it with your own tools. The other issue has to do with Google’s policy on privacy. Google won’t give out details on users’ IP addresses, nor will it allow you to connect specific session details to users’ Internet addresses. There’s even a clause about it in its license agreement.

Lastly, there are some important limits to free analytics for the larger organisation to consider. One is the limit of five million page views per month (at which point you need to connect it to an active Adword account). You also have a limit of 100 website profiles that control access rights and a 25-site limit per Google Analytics account. Many of these can be worked around, but you’ll want to think through the implications for these limits in larger organisations.

Overall, Google Analytics is a good tool for understanding high level traffic patterns for your website, and strong value given that fact it is free.

It is important to note, however, that the requirements for demand generation websites are changing. While it’s hard to argue with the free price tag, you’ll need to evaluate the potential impact of other solutions that can help you improve lead generation, conversion rates and even improve sales.

Like everything else in life, there is no free lunch. You get what you pay for, so make sure you evaluate what you get, and what you do not get from services such as Google Analytics.

Darren Guarnaccia is VP of product marketing, Sitecore.