Judah Phillips of Metrics Insider lists the following challenges for mobile
analytics:
• Not all mobile browsers support JavaScript, meaning that the most
common method for collecting data is not available on a lot of mobile
phones. Mobile analytics packages have had to come up with alternative
implementation methods like packet-sniffers and accessing log-files.
• Handset capability detection: This can be a challenge for some
packages, and is not offered as a rule. If this information is important
for your site, you may need to carefully investigate the analytics
package you use.