<< We divided our customers into cohorts, looking at the new customers who joined each day as a distinct group. Then we could ask, “How did today’s customers compare to yesterday’s?” And, much to our frustration, the conversion rates were almost exactly the same. It was easy to get conspiratorial. It felt like each group had set up a conference call with the previous group. “How many of you bought the product? One out of a hundred? OK, good, we’ll do that, too.” >>

This is so true. I've seen similar user behavior at almost every website I've worked on or built.

The good news is that it's hard to screw up your own website with new features. Also that despite how hard it is, many competing websites will add so many new (bad) features that eventually they will succeed in screwing up their website.

Sometimes I wonder if this is why Craigslist has "won" for so many years. Not in spite of having so many competitors adding new features, but because they have had so many competitors adding so many new (bad) features.