Show me your organic traffic and I'll tell you how is your SEO
It takes time to find an interesting topic and dig it deep but it's "summertime and the living is eeeeeaaaaasy" that's why not writing much lately.
While I'm finishing my next article here you have one to make you think from a certain perspective how your effort (or no effort) to get natural visits performs
Talk is cheap Show me the code
That was a Linus Torvalds message to linux-kernel mailing list and applies for any other aspect of life including search engine optimization as well. I don't want to hear how great SEO you are or your company has hired, just show me your charts.
Go to your analytics tool, look for your organic traffic report and select the maximum range of time possible, since the beginning of your stats.
Let's see how they look like and we'll guess how it went through time.
Doing nothing and being lucky
If you have no paid any attention to your non-paid traffic from search engines there are two possibilities.
First one. You are somehow lucky and your stats did not went down along time because you still have some relevancy in your sector or niche, they didn't went up neither, just flat as infinite steppe.
May be you are receiving the benefit of some good links avoiding your ship to sink, a subdomain with better relevancy, big chunk of your organic is branded or who knows what indirect benefit you are getting.

Two years collecting data and an average of 1.350 visits month and that's it.
We did nothing at all
But your competence did so they are getting the biggest part of the cake while your bites are going smaller and smaller.

In three years and a half monthly visits went from 20.000 to 5.000, 75% less. you didn't save money, you've lost it!. Not the king of the hill any more but good news, is time to fly forward and get the crown back, you have to be brave thuogh.
Oh boy! Something went wrong
Or you are playing too hard in the edge of what is allowed by search engines stepping the line or innocently did something causing a remarkable drop in traffic.
it doesn't mean necessarily your site has been penalized, it could be your IT guys playing Russian roulette with redirections or any other fabulous idea they have from time to time.

In 7 moths time span, monthly visits from organic traffic went from 154.000 to 76.000 in an eye blink, 50% down, great job amigo!.
And doing something right (finally)
The best sign of a good ongoing SEO is a chart like the ones below, climbing up slowly but surely.

Two years and a half after web launch from 280 to 2.300 monthly visits, pretty cool for a very small corporative site.
This is another nice example in a quite competitive business area, by the way.

15 months later from almost 0 to 6.900 monthly visits.
Summer, a nice season to step back some steps, life in perspective and take decisions for the next hard winter, don't you think?