These metrics are really important for companies to have a metric point of company strength. Airbnb picked nights booked as their metric because it matched both what a host could provide and what a user was booking, but it is also decently easy to game. A team could game it by subsidizing stays, inflating listing, etc, if it became a mark of success rather than a metric, and it would cause short spikes but, in the long run, it would lead to negative reviews. For a company like Facebook, measuring a specific number of friends in a specific number of days leads to the user having enough “social density” to come back and spend more time on Facebook. In theory, a team could game the metric but creating fake profiles or by spamming friend requests to people, but that would mean that those who came back would see a drop in friend requests and wouldn’t stay far past that. The last company, Slack, picked 2000 messages after doing research and finding that retention increased significantly, because 2000 messages meant that they had moved from casual messages to detailed and thorough messages. This system could be gamed by making the word limit on messages smaller or including more automated bots and spam, but in the long run, users would be frustrated with the spam they’d have to wade through.
