“As a company grows larger, it can become more difficult to keep the invention machine humming, and one impediment is “one-size-fits-all” decision-making. In the same 2015 shareholder letter, Jeff wrote, “Some decisions are consequential and irreversible or nearly irreversible—one-way doors—and these decisions must be made methodically, carefully, slowly, with great deliberation and consultation. If you walk through and don’t like what you see on the other side, you can’t get back to where you were before. We can call these Type 1 decisions. But most decisions aren’t like that—they are changeable, reversible—they’re two-way doors. If you’ve made a suboptimal Type 2 decision, you don’t have to live with the consequences for that long. You can reopen the door and go back through. Type 2 decisions can and should be made quickly by high judgment individuals or small groups.” Prime was a two-way door decision. If Prime’s particular combination of subscription, free shipping, and quick delivery had not worked, we’d have kept tinkering with the formula until we got it right.”