Everyone here should know the benefit of deep linking with respect to improving how that particular page performs in the SERPs. But how much does deep linking actually benefit that site as a WHOLE in terms of Pagerank or other value spreading itself out?
In other words, which is more valuable: a deep link to a subpage from a PR6 site, or a link to the homepage from a PR3 site? Will that PR6 deep link spread some value and boost how the site ranks in the SERPs as a whole, or does the benefit stop at the page it deep links to?
As long as the deeply-linked page links back to others on the site the PR6 link will spread PR to the rest of the site just like a link to the homepage would (but obviously the majority of that PR would land on the specific subpage linked to as opposed to the homepage).