SEO Tip #46: How can I make sure Google reaches my deeper pages?
Matt Cutts: Well it’s unclear whether you’re asking about how many levels deep it is in terms of directories or how far it is from the root page.
One way that you can make sure that Google reaches those pages is link from your root page, your main page, directly to the deep pages that you want to be crawled. So we tend not to think about how many directories deep a page is, but we do look at how much PageRank a page has.
So if a lot of people link to your root page then you can link to subpages and then those subpages can link to other subpages and at some point we’ll stop crawling. So one thing you can do is you can try to make sure that as many pages as possible are within just a few clicks from your root page.
A good way to do it is prioritize which pages you think are the most important. Either they convert the way that you want or they have really good ROI. So don’t treat all of your pages the same. If you’ve got a few that are real money makers, try to surface those and get them linked to from your root page so you can make the most out of that.