Does user agent `facebookexternalhit` represent a user click?

Question

If I see facebookexternalhit as a user agent in my logs, should I assume it's a bot or did a Facebook user share my link?

To put it another way, if I paid for ads based on a CPC and only wanted to pay for human-initiated traffic, would this user agent be a positive, negative, or neutral value to me?

Answer 1

It is Facebook’s scraper reading the Open Graph information from your page. I can be triggered by a user sharing your page, but also for other reasons (f.e. FB updating the info on a link that was shared before).

No, you can not take that as a sign for human-initiated traffic. It would at most be “neutral”, but calling it “negative” would be closer to reality.