I don't think the referer info is ever really essential but here are some possibilities: 1) If you came from a social media site, maybe I'd highlight that part

I don't think the referer info is ever really essential but here are some possibilities: 1) If you came from a social media site, maybe I'd highlight that particular social sharing option in a share bar, or hide others. 2) In an e-commerce store, maybe Google sent you to some page on my site that isn't really the best for your search term (product discontinued, other better matching product), I can give you a link to that other page. Google isn't necessarily magical in its ability to pick the best page on a site for a specific term. Maybe if you come from a competitor I can highlight some content that compares my product to the competitor's. 3) I've never derived a ton of benefit from it, but some sites will highlight your search term for you on a page. It could possibly also automatically scroll you to a relevant section if it's a long page and what you searched for is an exact match for some subsection. In general it can be a valuable data point sites can use to improve the end-user experience. That being said, I can't think of anything where the value really outweighs the potential for abuse, but I think saying that it has no value to the user is short-sighted.