What is the best way to get a high CPM without having an extremely focused niche website? Is it possible to combine CPM ad companies to generate a higher CPM? Ideally, I would like a CPM of $5. Any CPM method is fine: adwords, banners, popunders, popups, sounds, full page etc.
I recommend using the content network on Google AdWords. You can pre-select which sites, you want your ad to appear on, and also predict the CPM in advance.
Admarket it looks as if MCJim was asking for a way to earn a $5 CPM and not how to pay it for his/her ads. Have you tried Google Adsense and CPM network ads put together. Although don't use to many ads on a page of your site as it turns of visitors and can be against network rules.