There are many different services that can be added through Posterous:
On Twitter – make sure you add your web address to your profile.
On Facebook – add a Facebook PAGE, using the Facebook Page Quick Start Guide found on Facebook. Can add websites to your Facebook page – which gives more banklinks.
On LinkedIn – you can add “My Company”, “My Blog”, “My Websites” – all of which give you links.
To manage all of these, add services via Posterous. So, add Twitter, Facebook Page and LinkedIn.
Take home message – always put your link into your profile on ALL services.