ClickTracks JavaScript Data Collector (JDC)
Web analytics buyers need to be aware of the way that data is fed into the analysis system, and the possible dependencies that are created between the website and the analysis engine. Different methods of collection have strengths and limitations related to accuracy, ease of maintenance, data privacy and ownership, scalability, and recurring costs.
All web analytics programs collect web visitor activity either by analyzing web log files or JavaScript page tags. Log files are generated by the web server for the site and are read directly by the web analytics program. JavaScript page tags (sometimes known as 'client-side tagging,' 'page tagging' or erroneously as 'cookies') require some lines ofJavaScript to be inserted into each web page. When the page is loaded in the end user's browser, a request is sent to a data collection server, processed and made available for analysis.
When faced with the decision to use a hosted service or a log file-based web analytics solution, the buyer has been forced to compromise.
Log file based solutions come with compromises.
Hosted services also come with compromises:
- Data privacy/ownership: With hosted services, your data is stored on a 3rd party server, viewable (and sometimes used & owned) by the 3rd party, along with hundreds of other businesses' collected data.
- Recurring costs: Hosted data collection requires monthly fees that rise with visitor volume.
ClickTracks JDC provides the accuracy and scalability of JavaScript page tagging while simultaneously delivering the data privacy, cost and data-ownership benefits associated with log file-based systems. To achieve this unusual combination of benefits, ClickTracks sells a licensed, productized version of its own hosted data collection software. This gives businesses the option to use their own secure servers to implement the same software that ClickTracks uses to collect and serve web analytics to thousands of customers worldwide.
Accuracy
Log Files vs. JavaScript Tagging
Log files have been around since the beginning of the web, though they've only recently become interesting to marketing managers. Within early versions of web analytics programs, log files would typically yield data like bandwidth, server errors, peak usage, and lists of referring sites.
More complex data requires more sophisticated analysis. Modern log analyzers like ClickTracks can also determine:
1. Visitor sessions: These can be determined with statistically acceptable accuracy if the analysis software is able to strip graphics files, then joins distinct pages into a single visitor session, actively managing issues caused by dynamic IP addresses and session timeouts.
ClickTracks uses well-established heuristic algorithms for determining visitor sessions.
2. Session accuracy: If a session cookie is available, session accuracy is improved.
ClickTracks works with standard session cookies generated by JSP, ASP and PHP. A custom session cookie can be configured in ClickTracks Pro and ClickTracks JDC.
3. Unique visitors: ClickTracks Pro and ClickTracks JDC can calculate unique visitors if a unique persistent cookie is available, and the Pro/JDC server is configured (see 'cookie tracking' in the Pro/JDC Server). A database is built into Pro/JDC that can read the cookie and map back to an original campaign, even if several weeks have elapsed between click-through and purchase events. This is sometimes referred to as latent conversion tracking.
4. Heuristics: Tracking visitors across multiple sites/domains is usually done by falling back on heuristics when the cookie is dropped. Cookies are often not transferred when the user moves from domain to domain, so a fallback mechanism is needed.
5. Robots and spiders: Robots and spiders are automatically filtered and placed into appropriate reports. In ClickTracks, a robot is identified both through simple user agent checks, and also via detailed pattern recognition within the session.
Problems with Log Files
Much has been said about log files and their disadvantages. To summarize:
They aren't plug and play: Although ClickTracks can take advantage of both session cookies and persistent cookies, the fact remains that these must be present in the log file...and it's the responsibility of the website manager to set them. While there's nothing complicated about doing this, some companies simply can't gather IT resources needed.
