In which decade did companies like Crazy Egg begin selling specific heatmap analytics designed to track user interactions on web pages?

Answer

Around 2006

The commercial adoption of heatmaps for web analytics, tracking cursors and clicks, took off around 2006 with companies like Crazy Egg meeting the rising demand created by increased internet traffic.

In which decade did companies like Crazy Egg begin selling specific heatmap analytics designed to track user interactions on web pages?
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