I have been thinking on and off about Posterous since I first used it and decided to put my thoughts down in a post. Nischal asked the question "Would you stick to Posterous?" My answer today is "No" for the simple reason that it's difficult to make the commitment to use Posterous as my primary blog until custom domains are supported. Redirects just don't cut it.

Also, the brutally honest truth is that Posterous is on borrowed time. If the service does not start innovating rapidly, get huge user adoption and then create a significant reason for users to stay, it will soon become irrelevant. Its primary feature -- email to blog -- is not enough of a differentiator because technically it is not very difficult to implement and other blog engines will be quick to offer it to their users (some already do).

I think Posterous should be thinking about ways in which they can continue to stay relevant and even attractive to bloggers by doing the exact opposite of what they are doing right now. Instead of trying to be a blogging platform, they ought to focus on being an email publishing utility very much like FaceBook is positioned as a social utility. The AutoPosting capabilities available on the service are a great way to start, but they could be so much more. Instead of just supporting vanilla posts with title and body and hosting the photos/media here, they should go all out and implement email to MetaWebLog and other API's. Being able to use email to make a complete, detailed post to WordPress, DasBlog and other blogging engines would be great. Add template, tagging and categorization and it starts to get really interesting.

And while they are at it, they should do it for not just 10, but 100's of other services. Basically, email enable every ProgrammableWeb.com API for which email posting makes sense and that has any kind of traction. That would be killer and greatly increase the barriers for competition as users don't like changing habits unless there is a very good reason. Imagine "posterous" becoming a verb for "posting something to any web service using email." I think this would be a bigger opportunity for the company and allow it to become truly indispensable compared to where it is now -- a "me too" blogging platform which re-posts to other services.

Bottom line, forget the blogging and focus on the email.