If you only want your home page to rank, can you use rel="canonical" on all your other pages?

[watchcases]

If you have a lot of pages with 1 or 2 inbound links, what would be the effect of using rel="canonical" to point all those pages to the home page? Would it boost the rankings of the home page?

As I understand it, your long-tail keyword traffic would start landing on the home page instead of finding what they were looking for. That would be bad, but might be worth it.

[JoshGill27]

Lucas,

If you did something like that you would be negatively affecting how many pages that would show up for your site in Google. If you rel="canonical" all your internal pages to the homepage you are in effect telling Google that all of your other pages are duplicate content and that the home page is the only piece of original content on your site and Google will take that out of the listing. If you weren't going to use those low linked to internal pages you could do a 301 redirect those pages to the homepage. By doing that the majority of link juice from those pages would flow to the homepage. The effect could be minimal depending on the quality of the links pointing at those internal pages being redirected, but if they were high quality links then it could make an impact. It will probably take a couple good weeks for Google to make the adjustments.

[john4math]

rel canonical is for letting search engines know that a page on your site has duplicate content of another page.  However, I doubt all the pages on your site are duplicates of your home page, so the most likely outcome is that the search engines would ignore your rel canonical tags and just index the pages as normal if they're not similar enough.

This is not really the intent of the tag, and to me it sounds like it falls close to the black-hat side of things.  If you really want the rankings from those pages, and don't care about them, you can 301 redirect them to your home page like Joshua suggested.

Here's the SEOMoz post from about a year ago about rel canonical.  It also links to some good resources: http://www.seomoz.org/blog/complete-guide-to-rel-canonical-how-to-and-why-not

[KeriMorgret]

Here's a post from Dr. Pete about doing just that. He lost traffic, he lost indexed pages, and had to beg to Google for a reinclusion request even after he fixed things back again. You don't want to do it.

http://www.seomoz.org/blog/catastrophic-canonicalization