When you're about to publish a new piece on your blog, you might wonder if (part of your) your title is unique (enough). There's a Google Search operator you can use to check the originality of a title.
Simply type inposttitle:"your title words" to verify how many other articles are using a title featuring your phrase.
See for instance how many pieces were written featuring the exact sequence "spy on your competitors". I get approximately 1,110 results.
Interestingly, according to SEMRush, there are just 10 requests per month on Google USA for this specific query. So 1,000+ pages are fighting for a rather limited pool of searches.
In terms of wording, "spy on your competitors" is 2+ more popular than "spy on your competition". It's more personal.
Let's try something else. Let's see how many people are using "15 ways to" in their title vs "21 ways to", to see which one is the most popular among bloggers.
Most bloggers didn't make the effort to try to find 6 extra ways to do something ;-) I'm pretty sure that if we push it further, to 31 ways for instance, we won't get many results (I'm using odd numbers since they're usually more popular in blogging).
FYI, at time of writing, "41 ways to" gave back 23,700 results and "51 ways to" 4,400 results.
Which proves that you have less competition when you're using what Brian Dean names the Skyscraper Technique, i.e. creating longer listicles than your competitors.
You will probably find many use cases for this inposttitle: Google Search operator, besides checking the originality of a title.
PS: the title of this post is... pretty unique ;-)