I've read around here that depending on the ad, it is of different value per click. How is this determined? Is it basically luck or do you have to reach a certain status before you can get ads that pay a high amount per click?
It's about supply, demand, and how much people will pay for it. The higher people are willing to pay to be on your site, the more you will earn. If you have a low-niche site, you won't get that great of earnings. If you have a site people are willing to pay top dollar to be on, you will get great earnings. Simply as that really.
there are several bid tools out there, but none of them can really tell exactly, since we dont know exactly how much google keep, plus it is just too random these days to predict
The only bid tool out there that is accurate is the one for Overture which means it doesn't apply to AdSense. There are lists of keywords out there that are high-paying, but again, like we have all said, there is no way to be exactly sure how much each keyword is. You could try bidding on those keywords via AdWords to see how high you would have to go in order to reach those keywords, but still there's no way 100% to know.
IMO you can't use Overture 's bid tool to find how much adsense pay for a keyword. I 've found some keyword with $1.50 different for payout. It also depend which Ads is being click, same keyword but different Ads can have different payout
I agree with Samskpunk. Overture has completely different results. In my opinion, i bet Google uses a random number generator to figure out keyword payouts
In reality there is no way to predict what you are going to make, even if there was a bid tool to show you highest bids for particular ads, chances are that those top paying ads are going to hit daily budget in first couple hours (unless your niche is highly unpopular) of the day, since they will show up atop all other ads , so then the ads with lower bids will move up and so on, so at the end of the day you might be getting ads that bid as low as 0.01 because all the ads with high $ are out of their daily budget. For instance, first couple hours of the day sometimes I catch something unbelievable as couple .75 - 1.50 clicks, and then the rest of the day ave.CPC is about 6-7 cents, and then last hours of the day it will be as little as several clicks per penny