I'm looking to build a network of websites that are similar in function but have different subjects. Similar to www.About.com. This is a SEO as well as General Marketing question. Is it better for SEO, Branding and Type in Traffic to have one site with sub domains for the different subjects or a different domain and site for each one? Thanks.
To start an authority site like About.com, you will need thousands of contributors. It's probably not feasible now that website businesses actually have to be profitable. As for your question: it doesn't matter how you link them as long as your network of sites links to your main site. With a huge amount of "authority" content, you should be able to rank fairly high for any keyword.
What about in regards to the amount of work it would take to build up the SEO authority of the site. Would subdomains not benefit more from the residual authority over separate domains connected by links? In regards to branding and repeat traffic is it easier for users to remember and use if there is one main url with subdomains for the individual categories?