Https & http urls in Google Index

[Geosem]

Hi everyone, this question is a two parter:

I am now working for a large website - over 500k monthly organic traffic. The site currently has both http and https urls in Google's index. The website has not formally converted to https. The https began with an error and has evolved unchecked over time. Both versions of the site (http & https) are registered in webmaster tools so I can clearly track and see that as time passes http indexation is decreasing and https has been increasing. The ratio is at about 3:1 in favor of https at this time.  Traffic over the last year has slowly dipped, however, over the last two months there has been a steady decline in overall visits registered through analytics. No single page appears to be the culprit, this decline is occurring across most pages of the website, pages which traditionally draw heavy traffic - including the home page.  Considering that Google is giving priority to https pages, could it be possible that the split is having a negative impact on traffic as rankings sway?

Additionally, mobile activity for the site has steadily increased both from a traffic and a conversion standpoint. However that traffic has also dipped significantly over the last two months.  Looking at Google's mobile usability error's page I see a significant number of errors (over 1k). I know Google has been testing and changing mobile ranking factors, is it safe to posit that this could be having an impact on mobile traffic?

The traffic declines are 9-10% MOM.

Thank you.

~Geo

[Geosem]

Hi DennisSeymour,

Many thanks. I agree with your assessments and have communicated these conclusions to my client. So hopefully I'll see some positive changes soon.  There's been a steady traffic decline year over year. The individual keyword tracking wasn't great a year ago, so it's difficult to say what keywords are driving the downward trend. I'll keep chipping away at the imperative tasks.

Thanks again!

[DennisSeymour]

Part 1:

I would definitely get that fixed asap. I would also check analytics (add in a separate https if you haven't) make sure analytics is actually tracking each page, http or https

Are you tracking rankings though? Have you seen any dips? Have you seen any trends declining over the months/years? That might also be affecting your traffic so it might be a combination.

Part 2:

Definitely. You have to check your site and optimize it for mobile. IF that is really a valuable part of your strategy, then you have to look into that ASAP. They are really big in usability right now and they even show a rating in the their pagespeed/insights tool for mobile. Be sure to fix the issues.

Since it's an old site with that much traffic, you might want to start doing a content audit as well.

Good luck!