We are in the SEO industry for a while now, wearing many hats: digital marketers, tool developers, advisers, researchers, copywriters, etc. But first of all, we are, just like you, site owners. And we’ve been through ups and downs regarding organic traffic, and we were in the situation of trying to understand why the Google traffic dropped dramatically at some point as well. Having all these in mind, we’ve thought of easing your work, and we’ve put together a list with the top 16 reasons that can cause sudden traffic drop, unrelated to Google algorithm changes or penalties.
I don't generally think of my own list as a traffic source, because those are people that subscribed and keep coming back, mostly because of good content. This is more tutorial about where to get fresh traffic from in case a person is not using some of these sources already. Where have you guest posted, I haven't seen any, would like to read some of those :)
To find the right people I downloaded a list of some of the most popular users within the community. To do this, I used Screaming Frog SEO Spider to gather a list of all the URLs on the website. I then exported this list into an Excel spreadsheet and filtered the URLs to only show those that were user profile pages. I could do this because all of the profile pages had /user/ within the URL.

But now, that is all changing. We can still see all of that information ... sometimes. Things got a whole heck of a lot more complicated a little over a year ago, when Google introduced SSL encryption . What does that mean? It means Google started encrypting keyword data for anyone conducting a Google search while logged in to Google. So if you're logged in to, say, Gmail when you do a search, the keyword you used to arrive on a website is now encrypted, or hidden. So if that website drilled down into its organic search traffic source information, they'd see something like this:
A few links down and I've noticed that Brian has a link from WordPress.org. Not bad! Turns out that his content has been referenced within one of WordPress's codex posts. If I were to reach out and offer some additional insight, citing one of my articles, there's a chance I could bag a similar link, especially considering they have a 'Useful Resources' section.
Clean, fast code is important and you need to be aware of this if you’re using WordPress themes or other CMS platforms that typically come with a lot of bloated code. Despite its chunky build, one of the key benefits of using WordPress is its structure of templates that allow you to create new pages at the push of a button and create content in a visual interface, rather than code everything yourself.
Unfortunately, this particular client was fairly new, so as a result, their Moz campaign data wasn’t around during the high organic traffic times in 2015. However, if it was, a good place to start would be looking at the search visibility metric (as long as the primary keywords have stayed the same). If this metric has changed drastically over the years, it’s a good indicator that your organic rankings have slipped quite a bit.
Forum comments work much the same way as blog comments, except you tend to lack the base post from which to play off. Instead, you need to invest some time into getting to know the culture of the forum, the prominent users, the rules, and the discussion flow. If people generally post one sentence at a time, adding a 3,000 word post will be excessive and may be mocked. If people tend to post lengthy discussions, short posts may have a negative effect. And, like Reddit, some sites may be very rabid about enforcing no advertising.

For our client: We rolled out numerous new pieces of content onto their blog and news section; we aimed to make the content creative and funny. As the client was in the careers space we made use of “funny interview questions” and “technical interview questions” style articles. It was amazing that one of the articles even made it to the first page of Reddit. We also pushed out content which was related to various holidays in that year and also specific to the client’s industry and also current trends in the market. 

Secure (https) to non-secure sites (http): Since Google began emphasizing the importance of having a secure site, more websites are securely hosted, as indicated by the “https” in their URLs. Per the security protocol, however, any traffic going from a secure site to a non-secure site will not pass referral information. For this issue, you can correct by updating your site to be secure through a third-party SSL certificate.