HTTPS

HTTPS is the secure version of the HTTP protocol that encrypts the connection between browser and server so data cannot be read or tampered with in transit.

Today HTTPS is a baseline standard, not an advantage: browsers mark a site without it as “not secure,” and many modern browser capabilities work only over a secure connection. From a performance view, HTTPS adds a small cost — the secure (TLS) handshake adds a step to establishing the connection — but that cost is small with reused connections and newer protocol versions, and trivial against the security. It also has an important side effect on data: when a user moves from a secure page (HTTPS) to an insecure one (HTTP), the browser wipes the referrer header, which is one reason a source signal gets lost and traffic falls into the Direct bucket. So HTTPS is both a security requirement and a factor in acquisition data quality.