[bdunn]

We're constantly reworking our marketing site, but to make it more technical for the HN crowd (our audience is mostly marketers), it's an "if-this-then-that" engine for your website.

- If referred by foo.com OR came over with particular UTM params OR landed on /foo THEN change out testimonials to be able foo (using similar underlying tech that Optimizely, et al use)

or

- If visitor, who has opted in previously, has the "Customer" tag in the ESP/CRM that our customer has linked their site to, then ditch the signup form on the homepage and put a training video (or something)

It's basically a rules engine that looks at on-site behavior (pages viewed, referring domain, query string params, cookie data, etc) and allows you to combine that with ESP/CRM backend data (tags, custom fields, subscriber vs anonymous), and make content changes (replace text, hide an element, swap out an image, etc) as a result of a visitor belonging to a particular segment you've defined.