IMHO I pay attention to "Bestseller: Amazon Kindle #[number]" or "Bestseller: Amazon Kindle Romance top 100".
Amazon bestseller with no specifics has become meaningless since the SEO crowd started selling getting on some subcategory with no other books in it as a way to get ahead on Amazon.
Makes sense to me
We've had several books in the top 200 and many in the top 500 (overall) but as I've said, nothing in the top 100 as of yet. They have all made top 10 (many #1) in their specific categories as well, but as you said, that doesn't mean much these days.
Mostly what we like to see is that our authors are making money and getting opportunities they would not have otherwise gotten, such as the film deals, international publishing deals with 5 figure advances, and the opportunity to move on to a bigger American publisher. We don't promise fame; no publisher does. We just promise to be extremely selective, provide quality to our readers, and put a lot of energy into helping our authors be more successful than the majority average.
We also promise that we are 100% human, and we'll make mistakes, and if we're smart, we'll learn from those mistakes . . . most likely only to make new ones! We're probably one of the few publishers that will make an admission like that, too; however, we are a down-to-earth bunch and not afraid to be "real" with people.
If I may make an observation, I think everyone goes into publishing wanting to get something different out of it. Some people think it's more important to be published by a "Top Publisher" even if their book only sells one copy per month. Other's don't care who publishers their book, they're happy so long as they sell hundreds or thousands of copies of their book each month. You will see this often, where people have almost no book reviews and no sales, but they are critical of other publishers who aren't in the top 100 even if those publishers sell hundreds more copies of each book per month--it's all about what is important to the individual, and there are no wrong opinion in that regard, IMO! Authors need to find the publisher that meets THEIR requirements.
Also, as we know, SEO isn't everything, or the all the people talking about SEO would be selling at least as well as our titles, right? Marketing and SEO definitely helps, but that's not all it takes for a book to be even mildly successful. Nor do all people see success as meaning a NYT best seller list. For example, I felt more success over my book being published by Harlequin (and a pretty nice advance for a debut author!) than I did over selling 20,000 copies of my book in the US via my own small publishing house. But I still see those 20,000 sales as success, too; that money paid bills and helped us through a hard time, especially when our baby was born prematurely and we had no insurance and had to pay for gas to drive to and from the hospital daily for six weeks and a sitter to watch our older three kids while we were gone. When it comes to success, it's all subjective IMHO. You define what success means to you (and it may mean more than one thing), then you find the publisher you believe can help you achieve your definition of success. We define success as making enough money off a book to pay some bills and gaining a dedicated fan base, but YMMV.
We've very happy that 5/10 of our authors have gotten agent representation since being published with us, 4/10 have received interest from international and bigger American publishers (one title already translated and published in two other countries), and 3/10 have received film interest (one has already sold the rights). Our authors are happy with their sales and most of our customers are happy with their purchases and dedicated buyers always waiting to buy the next book we release. I went into this expecting we would operate at a loss for two years, as most businesses do, and yet thanks to our talented authors and how well they have worked with the support we have provided them, we have really done pretty well overall.
If you are looking for a sure thing NYT bestseller, we are not the publisher for that, and we are not sure who is! We are just a selective publisher with a small list of titles, and who likes to see their authors succeed. What we give them is the tools and the exposure. As anyone in this industry knows, there is always a little bit of luck involved in what happens from there, but we're happy with "better success than most." We also get support many traditional authors published by bigger publishers and many indie authors who have self published--and we love to see ANY great book (whether published by us or not) making great sales and finding appreciative readers.
Our goal in 2014/2015 is to figure out how to sustain the success of our titles. Our better selling titles seem to sell hundreds to thousands of copies for the first couple years, then things die down. Our other titles (in less popular genres) may only sell well for a few months before dying down. We know this is common in publishing, but we appreciate a challenge.
I think the best part for us in all of this is that many of our authors want to publish second and third titles with us; several have had good experiences with other small presses, too, but prefer to work with us. We might not get everything right all the time, but we're glad we're getting enough right to make our authors and readers happy.