First to answer what metric is most important for SEO you need to answer what KPI is most important to your business.
Usually everything comes down to revenue, but sometimes it's the case that revenue is a result of a different KPI that our clients would prefer to focus on.
That being said 90% of the time our clients are concerned about their organic revenue going up. Everything else is secondary.
This list will examine each metric and explain why we've attached the weight to it that we have.
This is the holy grail metric... usually.
This is the easiest way to determine an ROI from your SEO efforts. It also is predicated on you knowing your numbers perfectly. You must have your conversion tracking goals set up properly, and you must know what dollar amount each conversion goal means to you.
If you're an eCommerce store this is extremely simple, as Google Analytics and plenty of other analytics platforms (like Kissmetrics) can tell you right away what revenue you're getting because purchases are being made directly through your site. On lead generation websites this isn't quite as simple, however you should be able to do your own calculations to determine your conversion value for each type of conversion.
For example if you own a web design agency and your average project value is $20,000 and only one out of 20 leads convert - first off you need to work on your sales processes - you would know that your lead value is $1,000/lead thus each new conversion is essentially ~$1,000 in new revenue.
Setting these goal values up in something as simple as Google Analytics will suddenly start informing you far better than ever before how much your SEO efforts are baring fruit.
We at SimpleTiger try to always have our client's conversion metrics as well set up as possible at the outset so that when our results start to pour in we can essentially give each client a direct ROI from our efforts - then the value of our services start to explain themselves.
Clients who do not have their conversion data set up properly will more often than not get very frustrated simply due to a lack of knowledge in the health of their marketing efforts. We try to avoid this at all costs.
Not all organic conversions are created equal.
Sometimes there are organic conversions that matter a very large amount to clients that go a little bit beyond direct revenue.
Some examples of these are email subscribers, ebook downloads, webinar signups, blog subscribers, contest subscriptions, even career inquiries.
At the end of the day though these are all still conversions - they're the final action that was taken on the site - which show us the true effectiveness of the traffic we're bringing in.
If we don't have these conversion goals set up then truthfully we don't know if the keywords we're targeting are actually beneficial to the end-goal. It's imperative that if there is a goal to be met on the site, it is being tracked with conversion goals in analytics. Google Analytics is free and easy to set up, and has very detailed conversion tracking.
After conversions and the end-goals take place, comes organic traffic.
Organic traffic is any traffic that is coming from a search engine. This means that it is not effected by paid ads, social media, or direct traffic.
This metric can be slightly deceptive because sometimes organic traffic will go down while organic revenue goes up. I've dealt with this plenty of times in projects where the keywords previously being targeted were essentially vanity keywords that did not have a strong focus on conversions, but brought in plenty of "bad traffic" and once we switched to high-intent keywords we saw a dramatic increase in conversions but an actual drop in traffic.
This is tough to handle from a client management position but we have to put weight behind each KPI and as important as organic traffic is, it's not as important as conversions and revenue.
An actual example that I have from a previous project I worked on was a florist in Boston (I won't name which one but they rank currently 1st and 2nd for "boston flower delivery" and 1st for "boston florist" in Google) that wanted to rank #1 for "boston florist" when they were still a very small business and didn't have the content, links, or local credit yet to rank for that highly competitive keyword. I did some keyword research and found that "boston flower delivery" had just as much search volume, nearly 1/3rd the competition, and was a far higher intent keyword - as people who typed that in were ready to buy immediately online.
We switched our focus (through a long while of convincing) to the higher intent keyword in "boston flower delivery" we immediately started moving up for that keyword, eventually hitting the #1 spot on the first page of Google. Their organic revenue went up over 250% month over month, but were about the same in organic traffic. This eventually led them to be able to invest more in their SEO which then led us to be able to do more local optimization and link building which led to their overall authority raising to the point where they could also rank #1 for "boston florist" and the rest was history.
Rankings are very important, they're pretty much where the rubber meets the road - but that being said they're so volatile that it's important to take their movements and fluctuation with a grain of salt.
Keyword rankings are an indicator of later growth and potential changes in priority in Google's eyes.
So when you see your keyword rankings go up you should usually expect to see more traffic from the keywords that went up, which hopefully result in an increase in organic conversions if you're targeting the right keywords.
When your keyword rankings go down you should usually expect to see less traffic for the keywords that went down, but also you should be on the lookout as to why that keyword went down.
Usually Google won't demote your rankings (unless you're doing something nefarious) but just bump you out of your spot so that someone who they believe is doing a better job of answering what they want to see answered from that search query. You should be trying to figure out what that is.
Does that page have better content? Is it cleaner? Are people staying on the page longer? Are people getting move value from it? Is the product better? Is the product getting more traction elsewhere and linked to? What is it about this page that is better?
It's a constant evolution where you have to be on your toes and understand what Google wants to see in their search queries, then backwards engineer that into your site.
This is why rankings shouldn't be the end KPI but simply a net indicator as to what is happening in your industry and what you need to adjust to stay relevant and ahead of the pack.
Some other KPI's that I wouldn't say should be focused on as the end-goal but more of a means to the end goal are metrics like time on site, bounce rates, pages per session, new users, average session duration, etc.
These indicate the value of your pages and the success your site is having in achieving Google's goal which is to align their users with the best possible content and answers to the queries they search for.
These metrics have been proven to help SEO rankings and thus affect your overall traffic.
If people are coming to your site via organic search, then bouncing 80% of the time, Google knows that what is on your page seems to not be helpful to their users - thus they will demote you in rankings or at least not count you as valuable as someone with only a 50% bounce rate. The same goes (sometimes) with pages per session, and average session duration where if someone is coming to your website and ends up clicking around and spending time there Google knows that your site is a valuable enough resource to warrant that action - so they will reward you as such.
Ev Williams actually once wrote a blog post about how Medium's main KPI was time on site (which they called TTR or total-time-reading) because if the amount of time someone spends on the site is going up then they know that the user interface is working properly and that the content they are reading is of enough quality to warrant their long-term attention. Traffic was not as big a concern for them because they knew that if they did that part right that the traffic would come as new content was published and shared.
I love this focus on a metric that they knew was important to them. If you have that in your SEO then you will be successful, but if you don't know what your KPIs are clearly you will have a buckshot approach and never be satisfied in your consistent growth.
Domain authority has been kicked around so much as a new "KPI" that I felt compelled to speak out about it. It's an interesting metric, but much like rankings it's more of an indicator than it is an end-goal. It's the hardest thing to move and at the same time it's something you shouldn't focus on moving. It's more of a score that you can look to and say "hey, how about that, that's cool" before moving on to things that actually matter.
Domain authority as defined by Moz (it's creator) is a "calculated metric for how well a given domain is likely to rank in Google's search results."
Domain authority is built on a logarithmic scale so you can rank anywhere from 1-100, 100 being the top sites on the web.
The biggest disconnect and misconception I see with this "metric" is that it is solely affected - and is a judgement of - your link building efforts. This is simply not true. Domain authority takes link metrics, trust metrics, and basically every other ranking factor into account and simply gives you a score based on that. If you think that link building will increase your domain authority on its own, you're mistaken - if you think that increasing your domain authority should be the whole point of your SEO projects you're mistaken.
This is a nice metric to see a cumulative rank of a site compared to other sites without going in-depth into the keywords they're ranking for, the quality of content that they produce, the locations around the web that they focus on engaging in, and the type of audience they have on social media.
For example, Twitter and Apple have the same Domain Authority of 100/100 if you predicated these businesses' SEO success on just this metric they would be the exact same.
Even though they have completely different purposes, target completely different users, and have completely different content on their websites. They are in no way the same.
If you took two companies within the same industry and did this same thing, one could be producing far better revenue numbers than the other and have far less domain authority but they're ranking for much better keywords and getting more conversions.
Another flaw is thinking that this is a score per industry, it's not - it's a grade that is democratized across the entire web. If you think a few links per month will increase your domain authority at a dramatic clip, you're wrong. It won't, it's something that you might look at yearly and say "hey we grew a bit, that's nice to see" but it shouldn't be a cause for alarm at the results of your SEO efforts if you've had a 300% organic revenue growth that year at a 20:1 ROI for example.
Define what your goal is at the end of the day.
Is it to make more sales online? Is it to engage readers in your blog? Is it to simply get more readers to your blog? Is it to get more page views? Is it to get more newsletter signups?
Whatever the case may be, it's important to determine your business goals first then match those with the most accurate metric that can be tracked for SEO performance.
Then set up your conversion goals accurately, and get to observing, tweaking, editing, producing, creating, and sharing and adjust course as need be.
Or hire us, and we'll help you with all of this!