As mentioned earlier on:
“Posterous launched in 2008. Our mission was to make it easier to share photos and connect with your social networks. Since joining Twitter almost one year ago, we’ve been able to continue that journey, building features to help you discover and share what’s happening in the world – on an even larger scale.
On April 30th, we will turn off posterous.com and our mobile apps in order to focus 100% of our efforts on Twitter. This means that as of April 30, Posterous Spaces will no longer be available either to view or to edit.”