Hello everyone 
I’m currently building my project on the Pro plan and still getting familiar with how everything works. I’d like some clarification to better understand things.
What I’ve noticed is that I’m getting ISR reads even though I’m not using ISR yet… so no ISR writes at all.
I see ISR reads when I visit the app in preview mode but also during the build.
What surprises me is that I’m not using ISR in my project yet.
Thanks, everyone !
Hey @michaelmoo0n are you using Next.js here? If so, I’m pretty sure this is due to the default caching behavior within it. I think Vercel will automatically use ISR if it determines that there are static pages that are fetching dynamic content at build time and/or if ISR improves performance. Overall this is just how Next.js and Vercel works together to help optimize your site/app.
Thank you for your response… I forgot to mention that I am using Next.js… I also guess this is normal behavior; I just want to understand how ISR reads works and why it is used outside of an explicit ISR setup…
I checked the documentation, but the explanations on this point are quite brief.
So if you have any insights on how it really works, I’d love to hear them! 
Hey, Michael!
Have you read @aldosch’s post on this? Might be helpful!
Thank you very much for this reference ! I just read it now, and it was very clear, I was able to confirm that I had a good understanding of the explicit use of ISR…
At the moment, I’m not using ISR at all because there’s no need to set it up yet… So I have no ISR writes in the usage tab, as expected.
However, I do have ISR reads. When I build, when I visit the app… which is counter-intuitive: I’m not using ISR, I have no ISR writes, yet I still see ISR reads.
That’s what surprises me, and that’s why I want to understand how it works…
Because I want to make Vercel one of my main tools, and I need to be able to answer a client’s question: “Hey, we’re not using ISR, but I see ISR reads in the usage tab, why?”