As a Business Owner who deals with a lot of first time authors and writers, I get a lot of people who use their profiles on social networks as their website. This is a big no no. Why? Let me tell you.
For one, most social networks like ning are private or closed. You must be accepted as a member before you can see anyone’s profile. So before you go giving out the link to your profile page, you need to make sure that people can actually see the page. Facebook is a good example. If you do not have an account with facebook you can’t see anyone’s profile on there. Unless you are looking for a page to “like” you can’t see the profile.
Secondly, when professionals are trying to post links back to you from their page, they get these long URL’s that make the article or write up about you look terrible. I personally do not use them. Instead I ask my readers to search that person on facebook and honestly how many times is someone going to search you unless they really want to like your page?
Do yourself a favor, get a blog or website. Don’t use social networks as a place of reference to find you. Yes of course you should let people know that they can find you here or there, that you are a part of this network and that. But to read more about you, your work, etc. give them a website or blog and then have a link to all of the social networks on your website.
Bottom line…it’s more professional!