I have a brick and mortar business which offers several services. These services have their own pages within my businesses website. Now, I have already built 10 tier 1 back links on the top 10 highest PR Web 2.0's available for my most primary service page and it is ranking well. I'm now moving onto my next service page. My question is, would you use the same Web 2.0's (with different sub domains due to the title being different i.e wordpress.abcde.com) or would you pick 10 other completely different Web 2.0's to get the domain diversity in your back link profile even though the page ranks may not be as high. Thanks.