But then I'd seriously challenge your assertion of
Only a relatively small percentage of webmasters use contentual ad programs for revenue.
Over the last month or so, I've been putting together a new business, for which I needed around 20 basic items from suppliers, in each case I wanted to have more than one single company as a supplier of each item, so as to prevent stock shortages if one supplier should be delayed or cease trading..
Researching* the various items has led me all over the internet..and I can safely say that apart from actual manufacturers sites and alibaba and it's ilk and wikipedia..almost all of the sites that I have landed upon ( many hundreds ) have had contextual ads on them..the vast majority provided by Google via adsense or Doubleclick etc..
My normal searches are not webmaster related, and the same thing applies to them..over half of the landing pages that I encounter are running contextual ads..and many are running "search" from Google..
Your search engine, or if you prefer your "brand", was not "in front of my eyes" during any of this searching, nor was it presented to me ..your rival Google, was however..many, many times..
This will be the experience of the average searcher, if they do not begin their search with Bing..they will not encounter it or the Bing name or brand or "products", anywhere..
* I don't begin my searches with Bing because despite my being able to supposedly select "show all" ( of the items I was searching for, only one is manufactured here in France ) Bing steadfastly chooses to mix in far too many results from France ( from pages mentioning the products ) at the top of your serps, and in the first few pages, even with my OS in English and my browser set to English.. Bing thinks that because I'm in France, that any old French language page or French hosted result with the keyword(s) in has to be more relevant to me than one from a non French website..
Even if I have made my search phrase very specific..( and even if I have chosen "English results only" ) this behavior is even worse if one of the keywords is the same in both languages..the Geo IP filtering on your serps is so "heavy handed" that I don't search with Bing..
Thus I never see your advertisers, and consequently will not purchase from them via your search engine..( I have over the past month, placed many orders, at least half from adwords advertisers, for 3 and 4 figure sums, and these just "initial orders" ) as long as Bing ignores my preferences and insists upon wasting my time pushing me results based upon where I am, your advertisers will not get my eyeballs , nor my custom.. I can read French perfectly well, but I don't want to have to wade through serps with French people asking each other where in France they can get what I'm searching for, especially when I already know that, until I launch my business, that they cant get the items anywhere..I already did more than enough "market research" :)
This heavy handed geo targeting means that I cannot recommend your search engine to any of the ( estimated 600,000 ) anglophones living in France ( many of whom are retired ) I may come into contact with, many of whom speak and read only rudimentary French..your "where you are is what you want a lot of in your results, even if you and your browser language settings** say different" is IME forcing large numbers of expats into the serps of Google..
**I know from the "strings" that you require from YPN "partners" when searches are entered, since the search results merger with Yahoo!, that one has to send, amongst the other data, the "browser language setting", that, combined with the searcher choosing "show all" or "only English" if taken into account at your end, "should" result in English language results only :) 't would be a start :)
( maybe people in other countries which use other languages have better luck "narrowing down" Bing serps to a specific language, other than the one used "natively" where they are, than I have ? )
You will be able to "infer" from my reference to YPN that it is in my interest that your ( now joint ) ad platform is successful, but you need to iron out some "wrinkles", such as the above..you could also talk to Yahoo! about not restricting "partners" to specific countries, but instead allowing use of a "feed" by an approved publisher / partner, to access / run on any "market", as Google do with adsense and adsense premium accounts.. ( The last "request" is not your decision I know :) ..but I thought it worth a mention.. "while I have your attention", I'd love not to have to send all traffic from outside my "market" to adsense versions of the same sites, taking off the "market" restrictions would be IMO a win for you, Yahoo! and "us" )..btw..by no means all of my sites run ads of a contextual nature ..some have contextual and direct ad sales mixed..some have no ads at all..