We all know that we should use web analytics to analyze the behavior of website visitors and the performance of the online marketing channel. However, what kind of web analytics should we use? Should I go for log file scanning or page tagging or a little of both? First, let’s define what we mean by these terms.
Page tagging involves placing a generally outsourced JavaScript code snippet on each page of your site and is sometimes called client-side data collection. Every time a visitor’s browser opens a tagged page, the script is processed and the visitor’s information is collected. Log file analysis refers to the data collected by your web server. What is the difference from a web analytics point of view?
The bad news is that both strategies have their advantages and disadvantages, so here it goes.
Labeling Advantages Page
o Because the data is collected on the client side, this avoids any proxy and caching issues
o It will give you information about web design parameters such as browser versions, platform versions, screen resolution, connection speed, etc.
o Track client-side events such as JavaScript and flash events
Disadvantage page tagging
o Firewalls can prevent or interfere with script processing
o Set up costs associated with code insertion.
o Code insertion can cause errors
o Will not detect page errors like 404
o Because bots ignore scripts they cannot crawl search engine spiders
o Cannot directly track non-html pages
o Provider specific
Benefits of log file analysis
o Historical data can be analyzed
o Reduced installation cost
o No firewall problems
o Track page errors easily
o Can crawl search engine spiders
o Independent of the seller
o Can crawl non-html pages as PDF files
Disadvantages of the log file
o Proxy / cache inaccuracies. If a page is cached, no logs are logged to your web server
oWithout web design parameters
o No event tracking
If you are used to looking at web statistics using Web Trends, for example, you may notice significant differences in the number of visitors. By moving to log file analysis, the number of visitors can increase by 20-30%. If your site does not use persistent cookies, your web analytics program cannot identify unique visitors, therefore all visitors are grouped as a total. Typically unique visitors account for around 20-30% of total website visits, so this metric will increase by this amount. Sometimes you will see a drastic reduction in visits to the site. Typically, this is because web analytics programs remove the burden of graphics that are mistakenly counted as visits by other programs.
Other differences in the number of visitors are often due to how the programs define a visit. A visit duration of 30 minutes means that multiple visits from the same IP address within this time period will count as a single visit. Change this parameter to 15 minutes and these visits could be counted multiple times and your total visits will increase. Finally, when a web browser loads a PDF file, different parts of the file are deleted at different times and some programs may count this as multiple requests for the same file. A good web analytics program will collapse these multiple downloads into one.
It’s important to understand these differences and manage your colleagues’ expectations, as surprise drops in website metrics can sometimes lead to disappointment when measuring website performance entirely.
For more information on web analytics, contact us at http://www.ju2.com and keep an eye on our blog at http://www.ju2analytics.com.