I haven't had that happen in a long time, and I'm suspecting that it no longer happens and that Google takes as many advertisers as as willing for any word. I tried a word just know and saw over 20 different websites with AdWords ads.
Does anyone know if there is still a maximum number of ads Google will show for any keyword? I liked it better when there was because it shut out people who tried to bid very low ($0.05) and take visitors to a one-page site full of AdSense ads.
...you'd get a message that your bid was too low and your ads wouldn't show up
beren, I wonder if you are thinking about a time, now long past, in which every keyword or keyword phrase had a unique Minimum Cost Per Click?
During those days (and I am so glad they're gone), if you entered a chosen Maximum CPC lower than the set Minimum CPC for that keyword you would get a message similar to the one you described.
Now, of course, every keyword has the same Minimum CPC - which is USD $0.05 or the equivalent in other currencies.
Does anyone know if there is still a maximum number of ads Google will show for any keyword?
Nope, no maximum number of ads.
I've been with AdWords almost since the beginning, and I actually don't recall that there was ever a maximum number of ads for a given keyword. Basically, any number of ads may appear for a given search, and the advertisers 'compete' for position via a combination of their Max CPC and CTR, as compared to their competitors.
AWA