It will make people uncomfortable, but this is standard practice in terms of event collection for analytics. Many articles here write about discovery from the side of a particular app or site.
If people reviewed some analytics solutions (many trials are available), then they'd see how pervasive this is and what product vendors are encouraging. The like's of Amazon have much more scrutiny around the use of data collected than those of smaller organizations. Obviously, they wield great market power so the concerns are broader, but an attacker has a much better chance of raiding smaller developers for volumes of data with much the same fidelity.