How Accurate is Google Traffic Estimator?

Wildly Fluctuating Totals When I Delete Words

[shelbeesmom]

I was doing a little playing around the other day on my campaign and I was checking to make sure EVERY word was relevant to the ad and when I deleted one that I didn't THINK went with the theme, I GAINED 70 clicks on the overall estimation.
Now for the question....is this accurate? And can I bank on it? If so, I will be playing around more often!
Thanks!

[jeremy goodrich]

>>is this accurate? And can I bank on it?

I wouldn't bet on their estimates being 100% accurate, but they're as good a guideline as you can get, short of clicking 'start campaign' and seeing how much traffic you get.

[shorebreak]

Our firm manages over a million keywords, and I can tell you with a high degree of confidence that the traffic estimator is 30%+ off 70% of the time.

It's gotten so bad lately that we're building our own work-around using historical data.

[cagey1]

Did you mean: Google Traffic Guesser

[shelbeesmom]

I mean the "estimate traffic" button at the top of the page in Ad group summary. Seems like when I delete certain words, I gain a tremendous "re-evaluation" of clicks...I was just wondering if this was reliable, or if it was just a "glitch" in the system.
I also notice that sometimes I cannot estimate traffic at ALL and I'm lead back to the log-on page. Seems like if I get over 700 keywords this occurs....
Thanks!