Social Bookmarking Query

[Young Samurai]

I use Incansoft's SocialBot for social bookmarking.

I register a new account (username) with the social bookmarking sites for each of my money sites.

So, for example, I've an account with Digg called Niche1 for all my bookmarks for my money site Niche1.com
and, account Niche2 for money site Completely-Different-Niche2.com.

Question 1:
Is it necessary to have different accounts with the social bookmarking sites for different niches/money sites?

Question2:
When I get an article published at, lets say, EzineArticles and I want to social bookmark it should I create another account with the bookmarking sites for this purpose or can I use the account which has been used to bookmark the same money site the EzineArticle points to?

I know this may not be the easiest dialogue to follow. Thank you for trying.