See those 200 status codes? They generally mean we’re all gravy, that people can uk email leads access that page, buuut it’s not so great in this instance. Letting bots and humans reach your site from two URLs, like www.moz.com and moz.com at the same time, is called a "canonicalization error." Say it 5 times fast, because that’s the only fun you’ll have with a canonicalization error. Below we see a redirect chain and a canonicalization error.

This is something you might not see in a browser, but when you're dressed up like a bot it’s uncovered. canonicalization errors make it harder for search engine bots to crawl your pages. And you’ll be wasting your link juice like a sprinkler on hot tarmac. We’re starting to find some answers to those bothersome "why" questions. These errors can be the holes in your otherwise solid ship. It’s time to go plug them up.