Of course it was the quality of the search results thanks to the algorithm (Page Rank) that at the time was unmatched and amazingly resilient, compared to the competition, against the primitive SEO tactics of the day (key word spamming etc.).

However, the lean interface without blinkentags and ads was definitely a selling point. Also, IIRC, the guarantee that you'd only get sites that actually contained all the words in your search query (that feature is long gone, too, of course).

I guess it depends how you define "selling point" exactly.

The interface and speed were great, no doubt. Did you ever encounter another search engine that produced similar or better results that you otherwise would have used, but Google's interface sold you? I never did, so it wasn't a selling point for me.

There was a time when google's search web page was under 16kb.

I don’t have an image to prove it, but I remember google making it a point and bragging of having clearly differentiated ads (in pale yellow I think?).

It was a big contrast and a signal of classy goodwill, back in the age of replicating popups and garish blinking text.

Exactly this. I remember when it was just a couple small links in a yellow banner you could scroll past. Same with YouTube, the ads used to just be a banner under or beside the video but didn't interfere with the main content. Once the ads got invasive, I installed ublock and haven't looked back. I don't feel the slightest bit guilty about that.

For Google, the ads used to be on the right side. It was a big deal when they made you start scrolling past them.

Speed. Altavista, Dogpile, Metacrawler and the rest were slow, and Google felt instant.

For me at least, it wasn't that either. It was the quality of the results.

I would have put up with slow bloated adware Google results of early 2000s, compared to fast minimal sleek interface with results of Yahoo/Altavista/anything else I tried.

The results were good. I remember admitting that for many things I really could have used 'I'm Feeling Lucky' and bypass the SERP entirely, but I disliked relinquishing that much control, so I never made a habit of it. Today I don't think I could trust it much of the time.

Are you just re-emphasizing your point? I was trying to point out another differentiator that many people commented on at the time.

I'm not sure what you are unclear about, but yes I was re-emphasizing my point for you.

There were lots of "differentiators" that did not really matter, including speed. The differentiator was result quality, not how or when they were presented.

Yes. Altavista and Metacrawler worked really well. Google managed to be just a little bit leaner and faster still. They probably did start to have a bigger index at some point, though.

Yeah, the results were really that much better than any other engine. The fast minimalist design was also a selling point, though.