I have all 10 of my wordpress blogs hosted in a single linux account. When would it be a good idea to buy another hosting account if I want to set up more blogs? Should I be worried with just 10 domains hosted on just 1 IP address?
If they're intermixing with links, I'd be concerned. If you;re running them as separate sites with their own content, you should be fine.
I say, if they are all yours this will not hurt you. I would interlink the most relevant ones and leave unrelevant ones unlinked... unless you are selling items... then cross sell because you have created your own advertising channels and it might make sense to advertise your own products. .... something I need to do more : / Other than that, if you are thinking that you might benefit from an SEO viewpoint, then I hear your situation will not benifit you at all. Google is said to classify backlinks by IP addresses, and since all your sites are on the same IP then they basically count as one central source. To gain backlinks from your own other pages, the pages are reccomended to be hosted on a different c-class ip address. c-clas is like this 255.255.255.2555 a.b.c.d so a different in c class would be a different in the 3rd number set of the ip address