Q: Should we split our site content into multiple sites on different domains?

Dear Kalena...

I'm a webdesigner and I look after polish financial news website - besides this website is also wide knowledge base about different financial services and products and supports as well visitors with online financial advices - all of those services exist at one net address in different subdomains.

My question is: what do you think about splitting this service to a few independent domains with a bit different content but being every independent part densely linked with each other? Will it help to promote this service having links from completely different domain addresses than from subdomains of one address (as it is now)?

thanks in advance for your valuable answer

regards
Pawel