The concept of “concurrency control” is very important for startups. Concurrency control is the practice of knowing the number of visitors that your website can handle, and only allowing that precise number of visitors to enter the website. In other words, if your website can handle 1,000 visitors, you would make sure that the 1001st visitor gets a message to come back later. (If you want a more in depth look at this topic, read this great post by Ashish Soni over at Saas Interrupted.)
Why is this such an important thing for startups? Because startups need to satisfy their earliest customers above and beyond those customers’ expectations. You can’t allow a traffic surge to degrade the experience of ALL of your users, because those first users aren’t just customer, they’re the reference base that you need to launch your company into the huge market of “later adopter” (read “pragmatist”) customers, which is where most of your buyers live.
(Of course, the 1,001st visitor who is asked to come back later will NOT be a satisfied reference, especially if this is a common experience for her. To prevent that from happening, you need to monitor your site traffic diligently to make sure that your site is set up for the right amount of traffic.)