Apps: Web Data Collection: Building Blocks: Event data
The Value from page returns a value from the page. You will need to specify an element on the page from which to fetch the value.
Double click on the building block after you have dropped it in the Event data area to open the On-site widget and select an element.
For example, you can capture a text on a page or the content of a field that a user has filled in.
The Visitor plugins Event data returns a comma-separated list with all the plugins that the visitor currently has installed in the browser.