Website Visitor Identification?

Does anyone have any recommendations for rich website visitor identification?

Recently, I've landed on websites (without creating an account or really taking any action) and have had someone from their team reach out to me via email within the day.

There's no doubt in my mind that they identified me & my work email just from landing on their site, but does anyone know what tool they're using to do this?

I've used WVI in the past (even worked at a visitor identification company) but we were never able to get as granular as the exact person/contact info that was visiting our site. Are these people just taking a crazy accurate guess?