I have a general understanding of the difference between a population (set of entities under study) and a sample (a subsection selected from the population). However, I've been doing some work in PPC (Pay-Per-Click) and AdWords recently, and can't seem to grasp the population/sample difference in regards to that.
For example, let's say there are two Google AdWords ads. Users will click the ad and it takes them to a form which they can fill out if they choose to. Therefore, I have data on the number of clicks and the number of forms filled out. The question I'm trying to answer is which Ad was more effective at getting more clicks and forms filled out.
Ad1 - 300 105
Ad2 - 320 100
Initially, I thought that my sample was the two ads (Ad1 and Ad2), but that wouldn't be right as I'm really examining the number of clicks and forms filled out. So it would seem that the population that I'm examining is the clicks and forms associated with the two ads (Ad1 and Ad2) and my sample would be the number of clicks and number of forms filled out. Is that right/wrong? Thus, would clicks and forms be considered two seperate samples taken from the same population? Or is my population the same as my sample in this case?