Tracking tags are bits of code that enable ad serving, site analytics, audience-segmentation, and social sharing tools on websites. In other words, tags are what make the web tick. By the end of last year there were nearly 1,000 different tracking tags floating around the top 500 websites. That was over 50% more than the 645 unique trackers found in the first quarter of 2012, according to Evidon.

Those tags are pretty active, too. In many cases, one tracking tag installed directly by a site publisher might spawn others, and those still additional tags, and so on. Publishers and other data providers don't always know whether tag spawning leads to the dissemination of actual consumer data gathered on their sites, or if it is merely part of the cookie-syncing process performed to match a cookie ID in one system to an ID in another for ad targeting purposes.

While some argue these tag hops aren't a big problem, many publishers worry that tag proliferation happening behind-the-scenes actually leaks consumer data from publisher sites to places they'd rather it didn't go. Another concern: site latency. All those additional tags can slow down site load time.

What's happening on popular sites? Select a site below and this Evidon tool will show you the tag hops originating with each website, and the latency associated with each tag.