By chance, I discovered Bill Hibler’s blog where he openly displays details of his Adwords campains showing the $100’s that go down the drain testing things out.

Like one campaign that got 1 sale of $79 for an advertising cost of $486 where the average cost per click was $1.10 I think that if you are bidding a dollar plus per click you should be confident of your conversion rate based on prior history using lower cost clicks based on long tail keywords, but I think this was an experiment rather than a careful approach to limit losses.

Here’s an interesting quote from Bills blog:

At the same time we’ve been running this PPC campaign, other promotional methods like writing articles, marketing to our own lists, etc. have yielded thousands of dollars in sales. While I’m not convinced PPC won’t work for this particular site, it definitely has not been profitable to date. When we ran up another $200 in PPC costs for the site in January without a single sale, I temporarily paused the campaign.

p.s. this information is a few years old now so what is it like now doing PPC?