It depends. If the social media platform has character limits, it might be a bit challenging. But for platforms like Facebook or LinkedIn, long headlines can work well. They can attract more attention as they are more detailed. For instance, a post about a charity event with a long headline including the event details, the cause, and the organizers can get more engagement.
Yes, they can be. Since social media users often skim through posts, a long headline that tells the whole story can quickly convey the key message. For example, on Twitter, you can use a long headline as a tweet and users will immediately understand what it's about without having to click for more details.