Conversion rates for membership

The google keywords tool is not 100% accurate.  Don't get me wrong it is a great tool and extremely useful but the results are not to the penny.

For example for the key phrase "market research reports"  the keyword  tool tells me that for positions 1-3 the estimated CPC is £0.58    I am actually bidding £0.80 and paying £0.70 and achieving average position 2.3.  

My best suggestion is to use the keyword tool to select keywords and then start with low bids and slowly ramp them up checking the position daily until you have go to the position / cost / conversion that you want.

There are people around who will aautomate this process for you and no doubt they will be responding to your post, but for a modest campaign you can probably manage it manually.

PS in composing the ad check out 'keyword insertion'.  Very useful and seemingly under-used.  Could give you an edge.

Bob
Textor