Social email is all about timing. Using social in email is only effective if you deliver the information before your fans have had a chance to digest the content on their own. The tricky part is knowing when exactly that is. Here are some general rules about the lifespan:
Twitter: Twitter has the shortest lifespan of all of the social media outlets with only 18 minutes to hit your follower’s eyes. Include your best tweets in email as frequently as you’d like, because chances are, your followers missed it.
Facebook: The average lifespan of a Facebook post is 3-5 hours. This doesn’t give much time for your fans to engage, so include these posts just as the lifespan is ending so that they have a chance to see your content.
YouTube: 75% of all the views that the average YouTube video will receive happen in the first 20 days, but the average lifespan of a video is actually only 6 days. After the 6th day, the video has generally lost momentum and is overshadowed by new videos being uploaded. Let your viewers know that you have a new video out as soon as it happens so that they can be the first to share.