Tonearm - 12:26 am on Dec 3, 2009 (gmt 0) Profit from a sale - Total cost of converting a sale = True Profit
Otherwise, it's too easy to find other, more cost-effective sources online.
Which are those besides organic SERPs?
Cost per click X Average clicks needed to convert a sale = Total cost of converting a single sale
Can't we all just use a formula like this to make sure our bids are in line with profits? If we track a click through to an order, that order's profit should be used to help determine the appropriate bid for that keyword. The tricky part for me is determining what percentage of an order's profit should ideally be paid to Google. 50%? Orders generated by clicks which aren't trackable (such as in the example above) should be factored into this percentage.
Profit from a sale - Total cost of converting a sale = True Profit