[willu]

Unfortunately this only reinforces the mystical nature of SEO. 1. Why does Webmaster Tools tell you duplicate titles are a problem but changing them has no impact? 2. Why does repeating pin descriptions improve traffic drastically when we're told not to duplicate content? 3. Why do some changes have a lingering impact while others revert back to pre-change behavior?

That said, I applaud the scientific approach to coping with the black box.

[freebs]

Webmaster tools will tell you about duplicate titles even if there are only a few. A few duplicate titles won't penalize your rankings. Perhaps this is your case. I've definitely seen results for sites that have had 60% of their page titles as dupes.

You also have to realize that it's very important on what you are changing the them to. You should have done keyword research to see how often people are searching for particular terms. If you changed the title to be a non-duplicate but used some obscure words that a normal person would never use, you won't see many results.

Titles are just one piece of the pie, they should be consistent with everything else on the entire page, including the meta description, headings, content, image alts, links, etc.

[iopq]

The e-commerce site I worked with had the best relevance with the word "USD" since it was on every page. But you're not supposed to just repeat a word tons of times to get high relevance on a keyword, right?

[motherwell]

What makes you think that the solution they implemented was a good one, and should have worked?

[dangayle]

I agree. I took one look at their test and thought: That's missing the point. They actually don't care if the title tags would hash differently, they care if the title tags are descriptive of the content in such a way that the pages can be distinguished by a human or nlp bot.

But then again, what more could they do? Likely adding the board's owner would have had a much higher statistical relevance.