...a ratio between money spent on PPC adveristing and Money earnt? Is there an ideal ratio of $advertising : $sales ie for every dollar spent you earn x amount of dollars? what would be a good ratio to work towards? what are you working with at the moment? Is there a term for this ratio (I assume conversion ratio = number of clicks:number of sales) that I can search for?
Personally, I would imagin that the average for everyone, would be a loss. That is another reason why so many sites fail. But truthfully, there are some that can make their clicks convert and they are the ones that are on a winner. The amount of conversion rate I don't know, but for some it is likely to be probably a few hundred percent or even thousand and then with others it could just be about 10 percent.