Total Organic Search Traffic
Simply put, this is how many people are visiting your site as a result of finding it while doing a Google search. If you are putting effort into improving your site's SEO, your goal is for your organic search traffic steadily increase over time. You can easily view your organic search traffic using Google Analytics.
What you don't want to see is no change, a decrease, or sudden jumps or drops in traffic. If you do, it may be time to reevaluate your SEO strategy.
Traffic By Landing Page
It's super useful to monitor your traffic by landing page - that is, knowing which pages within your website are pulling in the most visitors from Google searches.
Take a look at your top 5-10 landing pages here and note what you've done to optimise each of them. Can you apply the same SEO tactics to optimise other pages on your site?
It's a good idea to know how many of your visitors are accessing your site on a mobile device. With more and more people opting to surf the web on their smartphones, you can bet that your mobile traffic will increase over time. Be sure to optimise your site for mobile to make it easier for smartphone users to browse, stay on, and return to your site.
Once you've determined your SEO keywords and optimised your site for them, you should be constantly monitoring your SEO keyword rankings. Where does each of your chosen keyword phrases rank on Google Search? Try to check this before you start working on your SEO so that you have a baseline to compare to - a "before" picture, if you will.
Position tracking tool from SEMrush.
There are numerous tools you can use to track your keyword rankings. If you've hired a consultant to look after your SEO, their SEO services should definitely include some sort of dashboard or reporting system that spells it all out for you. Otherwise if you're handling the SEO yourself, look into Serpfox or our personal favorite here at Captivate Digital, SEMrush.
We can't emphasise how important backlinks are to an SEO strategy. The wider you can spread a link to your website around the web (preferably having it appear on high authority sites related to yours in some way), the more your site will grow in traffic and authority. Both quality and quantity of backlinks matter.
There are some free tools out there that you can use to check your backlinks, such as Moz's OSE, Majestic, and Ahrefs. They will give you visibility into how many backlinks your domain and your individual pages have, the domain/page authority or trust of the linking page, and what anchor text is used in these backlinks (hint: It's better if your keywords are used as anchor text).
Average Session Duration
How much time do visitors spend on your website? Ideally you'd like them to stay awhile and click through multiple pages on your site. If they're not lingering and instead click off of your site shortly after clicking onto it (i.e. they "bounce" - see the next item on this list below), you may need to publish more quality content on your site or make your website more user-friendly, in order to entice your site visitors.
Other similar metrics you might want to look at in addition to Average Session Duration include Average Time On Page (how long they stay on one particular page) and Average Pages Per Session (how many different pages they view on one site visit).
Almost the opposite of Average Session Duration is Bounce Rate, which theoretically measures what percentage of your site visitors "bounced" shortly after entering your site. Google Analytics calculates this metric based on whether a visitor interacted with your site (by clicking), or if they entered and existed on the same page without clicking around.
Look at your overall Bounce Rate vs your Bounce Rate for each traffic channel. Are you getting more quality visits from certain channels more than others? For the sake of SEO, aim to reduce your bounce rate for Organic Search.