第十四课里，Keith Rabois 提到应该“关注那些不正常的数据”时举了两个例子，一个是 Paypal 的，一个是 Linkedin 的。而第二个例子很好玩，更适合讲另外一个道理，一定要做有知觉的产品：
One insight I have had over my career is what you, you kind of want to look for the anomalies...
... I was at LinkedIn and I saw this stat that made no sense to me. The UI of the site was a little different then. 25% of all clicks, maybe 35% of all clicks from the homepage were people going to their own profile. And that didn't make any sense whatsoever. It was in the settings, you had to go to the margin and find a link. It was 25-35% of every click at scale, so this is just invalid stuff. And it made no sense whatsoever. I had never seen UI perform that way.
I went around for weeks trying to figure this out, then someone smart, actually it was Max Levchin, said something to me and I was like, he was like, it's vanity. I was like, ah ha! People are looking at themselves in the mirror. Thats a very good answer, because they weren't editing their profile. Nobody has something to edit everyday in their profile. But they were just looking at themselves in the mirror every day because it made them feel good. Then you could test that with, if I had more content would I look at myself in the mirror more often? It turns out, you did. If you had more endorsements would you look at yourself more in the mirror? You did. So we figured out what was underneath the utilitarian product, the product the team thought they were building was actually more emotional vanity.
我喜欢有知觉的产品——这是做 knewone 时学会并养成的习惯。现在开发者可以利用各式各样的工具监控自己的产品每一处被点击、被查看的数据。
当我有机会与某个团队谈他们的产品时，我最喜欢看的就是他们分析数据的方式（要是连数据都不给看，那就不用谈了）——这是我做 DD 的最根本依据。
怎样才能为一个产品注入灵魂？Keith Rabois 其实在这节课里有回答的。他引用了 Bill Walsh 的一本书，The Score Takes Care of Itself 里的一段文字：
“Do you know how to tell if you’re doing the job? If you’re up at 3 AM every night talking into a tape recorder and writing notes on scraps of paper, have a knot in your stomach and a rash on your skin, are losing sleep and losing touch with your wife and kids, have no appetite or sense of humor, and feel that everything might turn out wrong, then you’re probably doing the job.”