I just got hold of a very nice site... pr4 with thousands of pages indexed, I'm sure it will give me great weight. I am thinking about doing an experiment and throwing all the weight to one ad. What's the highest amount of weight you have used on one keyword? What happened after you did it?
About 60k to a single phrase... ranking number six in Google for it.. and it brings like 3-4k unique a day. I have more weight pointing to this page for other keyword variations also.. in total, maybe 85k... 60k is for that one mega phrase.