Does content lock hurt SEO?

This is a great question Alex. I've just recently ran a month long test on two of my biggest sites using content locking. It was a risk running the test on valuable sites but I needed to know how they would be effected if any.

Both sites had over 100K pages indexed in Google before adding content locking. I installed the CL script across ALL pages except of course for home page, about, contact. All content pages had the lock.

I should mention I was using Adscend Media for my CL. I'm not sure if results will vary should a different script be used.

Anyhow, after 3 weeks of running the CL I found one site which had 167K pages indexed dropped to just under 9K! I was shocked. I hadn't expected such a sharp decline. So, I immediately removed the lock. Luckily, after 12-14 days ALL pages were back in the index.

The second site had 101K pages indexed and also experienced a decline to just under 7K pages. Again, after removing the script all pages returned to the index.

Obviously this affected my rankings for the period during less indexed pages. I feel lucky to have all pages back in the index and traffic back to normal.

So, my conclusion is YES content locking did affect my sites adversely. Now, I'm guessing there are content lock scripts out there which recognize the search bots and allow them through. However, I've never run a comparison test to make a conclusion.

I hope this helps.

Craig