I was talking to the owner of Sunspel, a website selling luxury menswear both online and offline, who came out with the statement “Adwords is not cost effective for us” (not for product-related keywords, only for brand-related keywords).
My main experience with Adwords was for Viners.co.uk where my adwords campaigns generated 50% of sales at a cost per conversion of around 10% of the average order value – so very cost effective, in fact the most cost effective marketing channel in that particular case.
Of course an adwords campaign will not be particularly cost effective if the keywords chosen are not relevant, if ads are poorly written, and landing pages are poor. But the point made by Sunspel was that there were too many competitors bidding on keywords like “T Shirt” or “mens clothes”, and with so much competition it’s difficult to push a luxury message vs. a price-based message.
To some extent I had it easy running campaigns for a site selling mostly cutlery, where the majority of traffic came for a handful of “cutlery”-related keywords. And there are fewer Adwords competitors in the world of cutlery than T shirts. But to a much bigger extent Adwords was cost effective due to constant optimization; stopping keywords and ads which were not cost effective, refining keywords and ads which were more cost effective; constantly looking for trends and opportunities in the long tail of search terms.