nimeshatbms - 9:16 am on Mar 26, 2007 (gmt 0)

I dont feel you can optimize your ads anyhow for a longer time period.... "

Thats not correct. The online market is continuously changing and you have to change accordingly. Also, you can still work on getting more profit by reducing CPC and increasing CTR, this is possible only if you experiment and there is not definite period for experimentation.