Originally Posted by Yo Adrian

You do need inbound links.. not only to get indexed but to have a chance at ranking for your target keywords.

Interlinking all of your sites is one way, but the best links are non-reciprocated links from other sites. There's a number of ways to get these and the process can even be automated, to some degree. To get these, you can do everything from buying high quality contextual links to building up social bookmarking accounts that include links to your posts.