This article misses one of the primary reasons for AV's demise -- we didn't update our primary index for several months just as Google was gaining mindshare. A ridiculously high percentage of our front page links were 404s, while Google was always fresh.

This was particularly bad because one of our earlier strong points was fresh indexes. Our ability to refresh the supplementary index on the fly was awesome. When you lose one of your primary strengths, it's noticeable.

I don't mean to minimize the downside of losing focus. That's one of the biggest lessons I learned while working there. I'd say that our failure to maintain a high quality index was directly caused by our loss of focus, in fact. But it's important to remember that both UI and the underlying index quality matter.

"What about PageRank?"

Eh, not actually unique to Google. Remember that Jon Kleinberg was developing HITS in parallel -- AV was well aware of the concept of measuring page importance using incoming links, and we had our own implementation. It may not have been as good. It's hard to tell when your underlying data source is stale.

Also, any AV article which doesn't note that we bought Elon Musk's first company is inherently flawed. ;)