But I mean, if you launch a feature, obviously retention is going to go up. All right, so i mean, retention has been up recently because of the photos. But focusing on things that are sustainable and scalable, so that when we launch more schools or go into the next market or whatever we do, we're going to set ourselves up to have the same success that we've had without hurting our self in the current position. Mark is incredibly good at keeping the bar very high on new hires. When you're quadrupling in size in terms of people, there's always a tendency.
不过，如果你推广一个新的功能，回访率就会明显上升。所以，自从相册上线之后，回访率就升高了，要关注那些可持续发展的，规模容易扩大的事物，所以当我们 向新的学校扩展，就是进入新的市场时，我们的目标是获得跟以前一样的成功，而且不破坏现有的水平。Mark在招聘新员工时，从来不会降低标准，当你需要将 员工规模翻4番时，大多数人总会降低标准。

You see it again and again and I know Tom Byers and many of you in the audience always talk about quality of people and maintaining the bar. But in practice, it's really easy to say this person doesn't match up in there, but does match up along so many dimensions. It would take six months to find the right person. And Mark has been extraordinary, as a leader in maintaining a very high bar and at time walking away from people who are receiving outstanding recommendations, but either don't fit from a cultural stand point, or they're not going to scale and they'd the wrong person a year or two from now.
我知道Tom Byers（斯坦福教授）还有在座的很多听众，经常讨论人员素质以及保持很高的门槛。可在实践中，人们很容易找到这样的借口说“这个人在某一方面不合适， 可在其他那么多方面都合适，要找到一个适合的人得花上6个月啊。”而Mark作为一个领导者，在坚持标准不放松这点上做的非常出色。他经常会放弃一些得到 强有力推荐的应聘者，要么因为他们在文化方面不契合，或者是因为，如果公司没打算扩张，那他们就会在一到两年内成为一个错误选择。

And that is certainly, as an investor and board member an ongoing challenge. How do you deal with that trade-off where you absolutely need an ad sales force, but at the same time, it's one person at a time. You just can't say let's go out and hire five good engineers or five good ad sales people and not have them be great. Because the B+ or A- people, you know it, they'll hire B's and B minuses. And this is a time in the company where you just have to aspire with each hire to get an A or A+ person. And it's easier said than done. I think that is one of the fundamental ongoing challenges.
对一个投资者兼董事会成员来说，这是个持续性的挑战。你要怎么样取舍，你急需一批销售人员，可是同时你只能碰到一个合适的要一个，你不能在找不到出色的人选时，就去聘上5个差不多的工程师，5个差不多的广告销售，本来想要B+或是A-的人，可结果却招来的是B或B-的人。在这个时代，公司应该有招进来的每一个人都是一个A或者A+的人才，不过，说来容易做来难。这也是一个根本又持久的挑战。