1) You can easily import your Tumblr posts on your shiny new Posterous so you won’t lose any of your content
-> that’s helpful, but not why Posterous is better . If I wasn’t going to use Posterous, that wouldn’t be a reason to switch over.

2) You can configure Posterous to automatically ping multiple services when updating your Posterous (Twitter, FriendFeed, Facebook etc)
You can do that with Tumblr too – my feed autoposts to my Facebook and Twitter.

3) Posterous automatically uploads your new posts onto your old Tumblr, a win-win option as you can always go back to your old Tumblr should you wish to.
Again, not a reason to switch, just a nice-to-have if you do (although, to be fair, it is *very* nice to have, so you don’t lose followers you had before the switch).

4) You can monitor how many times a post has been viewed in your side-bar widget, and how many people have favourited that post
This is certainly better than vanilla Tumblr, but once you start using Google Analytics, you get so much more information that it’s not really necessary.

5) You can also easily install Google Analytics and Feedburner onto your Posterous, something which I couldn’t do with my previous Tumblelog
Well… It’s certainly possible, and depending on how much you can fiddle with code, it’s relatively simple.

6) Your tags are visible in your Posterous’ side bar, making your content easily searchable (again I couldn’t do that with my old Tumblr)
Again, this is to do with the theme. Even if your theme doesn’t display tags by default, you can enable it by editing the code (obviously not so great if you have no knowledge of HTML, but still doable with online tutorials).

7) Once you’ve tagged your posts, Posterous will automatically recommend other users you should follow – blogging is all about forging online relationships, right?
That’s pretty cool. I haven’t experienced it yet, but it does sound good. No direct correlation to Tumblr, except to follow a few people who sound interesting, and see who they’re reblogging, follow them etc.

8 ) You can click on a user’s avatar to find out more about them – again I found Tumblr a little anonymous
Yeah, Tumblr has a tendency for that, but given that the Posterous information is put there by the poster, you could easily put more information about yourself on Tumblr if you wanted to. I guess it’s a different kind of community – some want to remain anonymous, others want to be better known?

9) The bookmarklet is dead-easy to install and use
As is the tumblr bookmarklet I’m using . Haven’t tried the Posterous one, but I’d hazard a guess that it’s much of a muchness.

10) Posterous are listening to their community and fast introducing new features
I don’t know too much about that, given that I’ve only just started. Tumblr doesn’t seem to have introduced a whole lot of functionality recently, but I haven’t really seen anything that’s necessary to implement, or anything people are asking for, so..

In conclusion, while I’ve liked what I’ve seen about Posterous, I don’t think you should necessarily switch from Tumblr to Posterous.
In fact, to start off, I think Tumblr is better – and at a later date, a switch to Posterous because it’s so easy to import all of the posts. Tumblr feels more intuitive for me and, while the email post thing is pretty simple, I like a more WYSIWYG interface for posting, for which Tumblr works pretty well.

That said, thanks for the post!

Still not sure where I stand on 'light blogging', but posterous actually looks pretty good from having a quick glance at your profile – that's the sort of thing I had in mind when I joined Tumblr. Maybe I'll transfer it over.