I'm all but certain that these suggested maximums are still current. I'll ping my tech contacts now, and post again later if I learn differently.
* Max suggested keywords in single Ad Group = 750
* Suggested max Ad Groups per campaign = 100
* Max suggested keywords in a single campaign = 2000 between all Ad Groups
* Max suggested keywords in an account = 50,000 (25 campaigns x 2000 keywords)
AWA
Are there any penalties for exceeding these suggested numbers?
Nope no penalties, vanderbolt - beyond possible navigation problems.
Many on this forum regularly exceed these recommendations by a sustantial margin. Just keep in the back of your mind that it is possible to hit a 'tipping point', beyond which navigation can get difficult in your account.
I've talked to a number of advertisers who have (for example) many thousands of keywords in an Ad Group, and many hundreds of Ad Groups in a campaign - and things seem fine until, well, they aren't fine anymore.
As for example, having to wait a minute between pages.
And at that point, btw, it's a real pain in the neck to seperate out the keywords/Ad Groups/campaigns so navigation becomes normal again.
So take the suggestions for what they're worth: suggested maximums, beyond which things may get difficult in terms of navigation within your account.
But other than that, nope, no penalties.
AWA
Do you have a suggestion for negative keywords?
In another thread, ginagina offered some excellent advice:
Have you checked your logs and compiled a list of negative keywords? I use 100's of negatives in my campaigns. That will really help to eliminate non-relative impressions and would explain why your ads aren't getting clicked.
To this advice I'd add that the 'natural' Google search results (on the left-hand side of the page) are an excellent place to look for negative keywords. I'd suggest looking through the first 100 or so - as many as you have time for - and see if any negatives suggest themselves. I bet you'll find a lot.
Do (negatives) count as a keyword or are they treated differently?
Negatives are not counted toward the suggested maximums per Ad Group/campaign/account. So have at it!
AWA