Facebook Developers has published an interesting article on best practices for developing apps for this platform. Here are the main recommendations (please check the original article for examples & screenshots):
1- “You must not incentivize users to use…Facebook social channels, or imply that an incentive is directly tied to the use of our channels”.
2-“You must not pre-fill fields that are intended for users to express themselves (like “stream stories”, etc)”
3-“Users must always consent to any Stream story you post on their behalf. If you do not use the Feed form which gives users the option to preview and customize their post, you must not publish a Stream story unless a user has explicitly indicated an intention to share that content, e.g., by clicking a button or checking a box that clearly explains that their content will be shared”.
4- “You must provide users with an easily identifiable “skip” option whenever you present users with an option to use a Facebook social channel”.
It seems like not all’s fair in Facebook 🙂
Source: Facebook Developers