Okay, now I'm curious. What are the criteria for NYT putting a book on their "best-sellers" list (and other sites like Goodreads if they used the same skewed measuring system). Is it some sort of deal with publishers?
Okay, this is going to be a bit of a rant seeing as this is the kind of inside baseball shit I live for.
Officially? Its a list of certain "select" book stores and retailers, mostly centered around the Northeast, that all the big 5 publishers and multiple PR firms all know about.
That regionalism is a big way the list backfires - say, an author who sells really well in the South or out west, or any publisher not based out of New York or Boston, is at a major disadvantage.
It's also ridiculously easy to put your thumb on the scale with the right connections and money to burn, and as a metric its useful mostly for dick measuring, not actual book sales.
Even then, the NYT gets final say and can choose to exclude your book entirely. I believe other members have brought up the most famous example, The Exorcist, whose author sued the paper unsuccessfully over that.
One of the most obvious ways they put thier thumbs on the scale is leaving older books off the list as much as possible (making exceptions for major boosts in numbers). To use my spec fiction background as an example, if they didn't do that, the genre Bestsellers list would be Tolkien, then Rowling, then a mix of big name back catalogs of guys like Robert Jordan, OSC, etc, whose decade old books sell more copies in a month than most newer authors sell in thier career.
I can tell you there are multiple marketing firms who literally specialize in rigging the numbers in your favor for the right price. Not to mention special interest groups - any time a major public figure or politician drops a book, rest assured various charities or PACs connected to them are buying thier book in bulk.
As a result there are authors who sell millions of books who never make the NYT Bestsellers List... and authors who sell less than 20k who made the list.
Goodreads is totally worthless. You can pay for a few hundred reviews for $5 on certain websites.
As for good metrics? Nielsen BookScan is the best. They track total sales numbers nationally, including digital sales, which the NYT does not. You also have to pay to access it, so most people never see those numbers.
For more casual measurements, Amazon isn't too bad, but thier numbers fluctuate a lot, and things like price or sales/deals can have an impact.
Long story short? If you want real nunbers Nielsen BookScan has them, or close to it.
Otherwise? Your best tools are your eyes. Look at your book stores and libraries, see what's actually on the shelves, and more importantly, what's selling and people are actually buying and reading.
Also, what ends up getting sent to second hand book stores or collecting dust in clearance bins. For example, you will notice most copies of Ellis' Axioms End are now making thier way from Barnes and Noble and Books-a-Million to Half-Price Books and 2nd and Charles these past couple months.
After that? Look at the authors themselves... a ton of authors who have "New York Times Bestseller" in thier bio survive and subsist off Patreon donations and grant money. Meanwhile there are "lesser" authors making a literal mint off thier work.
