Earlier quoted context omitted.
My memory says that wasn't such a big selling point. When Google first came out it blew all other search engines away in terms of result quality. If, back then, Yahoo and Altavista were minimalist and Google was a garish nightmare of ads and flashing gifs and nested banners and affiliate buttons, I would still have happily used it for the results. Google's search interface is still reasonably clean IMO. Nowhere near…
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…
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.