Google Analytics has acted as an effective way for advertisers to determine the success of and return on investment from marketing campaigns.
According to Google's website, it can show which pages drive the most page views and point out the least effective pages (ones with higher bounce rates). Advertisers can also set up goals to find out which people are most likely to convert from visitor to customer. In total, there are more than 80 different reports available.
With the newest version of Analytics set to officially overtake the old one in January 2012, Mashable pointed out some additional features that can be helpful in tracking ROI.
For example, keyword clouds now replace long lists of keywords, making it far more apparent which words are trending and getting the most hits.
Also, real-time data is now available - an upgrade over the previous version which forced marketers to wait 24 hours for updated visiter data.
Site speed is now reported to help determine average page load time - important because slower sites cost more and have a negative effect on quality score.
Lastly, social engagement tracking can determine which social platform a click or action occurred on, and tracks which visitors "+1'd" a site or how many people "Liked" it.