We manage large scale paid search for retailers. We help retailers improve site conversion. We're not a SEO shop. We don't have SEO clients. So it is with the curiosity and ignorance of an outsider that I'm listening in on the debate about pagerank sculpting .
Good idea or bad idea?
In the "dangerous and a waste of time" corner, we find Shari Thurow, who today on SEL advises you'd be wise to avoid sculpting. Her arguments are (1) spiders should experience exactly the same site as humans, (2) the nofollow attribute is a dangerous substitute for proper information architecture, and (3) SEOs will likely abuse sculpting so Google will likely soon ignore it anyway.
In the "OK but low importance" zone in middle of the ring, we have Adam Lasik from Google, who says sculpting is OK but advises the benefit isn't worth much time (see Lee Odden's video interview with Adam Lasik, question is at 5:32). Also there is Google's Matt Cutts, who according to SEMOZ, describes on-site no-follow as way for
webmasters to modify PageRank flow at link-level granularity... other mechanisms also work (e.g. a link through a page that is robot.txt'ed out)... There's no stigma to using nofollow, even on your own internal links; for Google, nofollow'ed links are dropped out of our link graph; we don't even use such links for discovery... The nofollow meta tag does that same thing, but at a page level.
In the "you betcha!" corner, we have Stephan Spencer rebutting Shari in a Sphinn comment today by noting his team has used the technique successfully for clients.
According to our tests, there are plenty of occasions where [sculpting] can be a valuable tool... If you have an ecommerce site and the category pages contain 3 links to every single product page -- the product name as a text link, the product image thumbnail as an image link, and the words "View Product" as a text link -- you could nofollow the image and "View Product" links and funnel more PageRank through the much more contextually-relevant product-name-based text links.
I'm not a SEO guy, and I am not speaking from data, but Stephan's arguments resonate, and the Google guys aren't blackhatting the method. For kicks, we may try some sculpting on this blog. SEO-savvy retailers might want to consider this approach. Let us know what you learn!