Adsense - Trying to Help with Context

I'm involved in a very large website which runs Google Adsense. I've noticed that on same pages, we don't succeed at getting contextual ads.  I'm trying to figure out what to do about this since I think the non-contextual ones earn less (less dollar per click, lower click through rate).  OFten, I don't even get an ad served up on these pages. 

List page not getting contextual ads!

 There are three reasons that I can think of that this"list"  page is not getting enough context. Some are easily solved, some are not.

1. The URL is not SEO-friendly. (see A) All the other pages on the site have SEO friendly URLS but on this huge site, 50 million monthly page views and over a million pages or word lists, we designed to manage our resources and did not implement a look up table for SEO friendly URLs. This is unlikely to get solved.

2. The text on the page, especially near the top, does not give much context.  In fact, looking at the code, I see:
We're  using some sort of standard text for the meta keyword and description. It's probably the same across all one million list pages.  It's really long too. The title tag seems to be picking up proper context by providing the grade level, school name, teacher name, city, and state.

I guess that this could be fixed by putting the words: "vocabulary list", "teacher", and "school" into the title tag. And the keyword and description should also be customized for these pages with this data. On the other hand, the page does have the school name and teacher name on it. This is not really less contextual custom text than are found on the other school pages, it's just that the balance is different since these pages have these long word lists which to a search engine, are so much gibberish. 



3.  The page is marked "do follow, don't index."  I wonder if that affects contextual ads?

School Page: Good success with Contextual Ads

In contrast, the teacher and school pages do have more relevant custom text on the page, they have SEO-friendly titles, and they are "do follow, do index".  For example, here are examples of teacher and school pages both of which have very nice and appropriate ads.

Another mid-term potential project is to allow teachers, parents, and students to put up more comments on their pages which would ultimately provide more original text (user generated) which would endear us to the search engines.

Or, if I let kids put up too much graffiti, I might get in heap of trouble.

Teacher Page, Getting Contexual Ads!