Using the estimator brought back different values for the the same phrase but different case; suggesting their may be a difference.
Although the estimator is generally unreliable you would not expect it to be fooled by this, so it kind of suggests keywords are case sensitive.
It's when you get a bunch of keywords and let's say you bid 20p for all of them and it suggests you'll get 50 clicks a day, so you increase the price to 30p and it says you'll get 40 clicks, so you reduce it back to 20p and it says you'll get 60 clicks, so you reduce it to 10p and then you will get 70 clicks.......
Just expect the unexpected.
Are we the only ones that prefer the latter?
If I were to advertise on the prime time TV show "Friends" and pay a premium for it, the television industry would not automatically show my ad on "Barney and Friends"! I think that aspect of adwords is absolutely rediculous.
Google should be the king of 'relevancy' and they miss the boat in this respect with adwords.
Overture's system is a little more to set up, but well worth the effort of putting in specifics.