Since opening the first cashier-less Amazon Go convenience store in Seattle almost three years ago, Amazon has continued to open new Go stores in a few additional cities. But if you’re wondering why there aren’t any such stores near you, it might be that Amazon isn’t sticking to its original plan to spread them across the country.

According to documents from 2018 viewed by The Information, Amazon planned to open 56 Go stores by the end of this year and 156 by the end of 2020, but so far it has only announced 18. Just 15 of those are open to the public and are only located in Chicago, New York City, San Francisco, and Seattle. Since the documents reviewed by The Information are reportedly from last April, it’s really hard to say why Amazon might not be sticking to its original plan — but we can speculate at a few potential reasons.

One idea: it might just be hard for Amazon to find good store locations. According to the documents, Amazon’s cashierless stores need high ceilings so the company can mount the cameras and sensors they use to detect which items a customer is buying. They also need to be near Amazon depots that carry fresh food, and they need to have decent foot traffic so customers are likely to stop by.

Another idea: Amazon may have reconsidered its bet on smaller stores as it explores building bigger ones. In March — the same month that Amazon suddenly shut down all 87 of its pop-up kiosks in the US — we also heard the company was planning to open a new grocery chain that wouldn’t be affiliated with Amazon Go or Whole Foods (which it owns), suggesting that perhaps Amazon believes a more traditional grocery model with a different Amazon brand (or no Amazon brand at all) has more potential than its other grocery businesses.

Back in 2018, according to the docs, it was already exploring a larger concept grocery store. Perhaps it decided to push harder on that.

And although Amazon hyped the Go stores as an easy, near-frictionless payment experience and has been testing it for a few years, Amazon is apparently still finding the right formula for how we’ll buy those groceries. The company said in April that it plans to accept cash at Go stores, which could slow down the in-store experience but also let more people shop. Just this past week, the New York Post reported that the company is considering biometric payments by way of scanning customers’ hands to pay for purchases at Whole Foods.

Amazon has also expanded its Whole Foods grocery delivery service in the months since its Amazon Go rollout plan was originally drafted — another friction-light way to sell groceries without needing tiny stores.

Amazon is also under continued pressure from activists criticizing its business practices, so the company could be taking a more careful approach to rolling out the Go stores as a result. When Amazon originally introduced the camera-heavy cashierless concept that watches you as you shop, it wasn’t taking nearly as much flak over its facial recognition tech. Or its tipping policy (since improved), worker conditions (stay tuned), or the massive local backlash over its supposed search for a new headquarters (now half-canceled).

Regardless of the reason for the slow rollout, it seems that something has changed with Amazon’s Go strategy since the projections made in the documents reviewed by The Information, and it seems less likely that we’ll see 3,000 of them by 2021 as we’d been led to believe one year ago. If you don’t live near a Go store now, you might have to keep waiting before you can shop at one yourself.

Correction, 1:12 AM ET: We re-counted and Amazon currently lists 15 Go stores that are open to the public, not 14.