I think what he was referring to was a common situation in which the user clicks on the link for the mobile version of a particular page, but instead gets directed to the root of the mobile site -- upon which there may or may not be a version of the page the user is looking for, and a link to which may be difficult or impossible to find in any event. That has nothing to do with ad deployment. It has more to do with laziness.
It's not that difficult to automatically carry content over to a mobile-formatted site. It can be a bother in the case of an old site that was created before mobile browsers were sophisticated enough for people to bother using them, but even then it's tedious rather than difficult.
All it really comes down to is isolating the content from the styles, ads, and anything else that isn't content; drawing it from a common directory for both versions; using CSS to define things like page format, images sizes and placement, and so forth; and using server-side scripting to create the markup (including ads and so forth). A single line of PHP (or whatever scripting language you like) in the header can then be used to automatically create links back and forth between the pages. It really isn't rocket surgery.
If you want to use different advertising strategies in the different versions, that's made simpler because the content is isolated. The respective heads can contain whatever scripting is appropriate to the versions; and the content can contain "includes" with relative paths (in PHP) to insert the ads that are appropriate to the format.
But what some webmasters completely miss is that if people can't get to the pages, they're not going to see the ads, anyway. Google's robots may find the the pages because they have nothing else to do other than follow links. But humans are going to give up after a click or three.
To even think about how to deploy ads before having an efficient and human-friendly content navigation system is backwards and sloppy. But I also suppose that in many cases, there's a lot more pressure from the suits to get the ad delivery system working than to make sure that people actually can get to the content.
After experimenting with all manner of ways to give users a choice between versions, I've found that the way users seem to like best is also the crudest: A little mobile phone icon with a link to the corresponding page on the mobile site (like this one):
and a corresponding text link back to the "full version" on the mobile page. I've given up on using scripts, providers, .htaccess, etc. to "automatically" detect browsers. I just let the user decide, and then keep him in the chosen root directory. If he changes his mind, he winds up in the root directory of the other version, but on the corresponding page.
It's crude compared to some of the other ways I've tried doing it, but it's also foolproof, works better, and liked by users.
I've also found from the stats that a lot of users on dialup connections prefer the mobile versions when accessing sites from a computer (presumably because they load more quickly), and that some mobile users with even crappy phones and browsers prefer the full version. Go figger.
Whatever the case, apparently I used to be alienating users by automatically making that choice for them using browser detection. So now I let them decide for themselves. But the link has to point to the right page or else it's all a waste of time, no matter how you do it.
-Rich
, ONE OF US!