Facebook announced some changes to its auto-sharing features for third-party apps that will take effect in 90 days. Facebook won’t allow any custom “verbs;” apps will have to make do for the time being with the existing built-in actions like Listen, Read, Watch, Follow. (Actions where a user clicks a button are still okay.) Facebook also said it would tweak its ranking algorithm to show more stories with images or locations in them, while it will prohibit “post to a friend’s wall” and some auto-authorization techniques.

Facebook’s rationale is that these steps will produce more consistent user experiences, and also increase story sharing and interaction. Of course, any time Facebook makes changes, apps and content companies depending on it for discovery cringe. It’s an over-reaction to say these changes foreshadow a disintegration of Facebook’s ecosystem and grand vision of social sharing and discovery. The ecosystem will watch for results, and chances are, if they’re completely disastrous Facebook will react quickly and change its policies and practices again. It has done so before.

But “chances are” is a shaky foundation to build a business on. Any developer must have back-up plans in place – including advertising, driving users to its own site and giving them a reason to stay, and vigorous cross-promotion.