Reading some comments, I get the impression that some don't understand what is WordAds so I am hoping to better explain it. WordAds is not an advertiser. So we cannot under-pay you or short-change you for your ad space. It's in our best interest and our mission for sites on WordPress.com to earn as much as possible, but I think you can understand that we cannot lose money and pay sites more than they earned from advertisers.
WordAds is a group of engineers, UI designers and finance people who serve as a conduit between you and advertisers. We have some influence on ad rates. Because WordPress.com is a top 10 global Internet site we can negotiate better terms with advertisers than a small site. But no company is big enough to demand much higher prices for Internet ad inventory. Most of the work we do is technical which allows us to test and run ads from a great variety of partners.
Most often sites that complain about poor pricing get most of their visits from countries like India, Malaysia, Indonesia or other countries where advertising is inexpensive. We simply can't force advertisers to pay much more for something that they don't value. Even in North America there is a limit to how much we can demand from ads. Sites like Facebook serve billions of ads per day and advertisers can buy that fairly inexpensively. There is no shortage of places where advertisers can spend their money and that keeps rates low.
Given that explanation I hope you can understand that its not possible for WordAds to be 'unfair' to bloggers. It is possible that we could be better at our jobs. There might be an ad partner that we haven't tested yet that might enhance your earnings. That's what we focus on.
Vaguereference you suggest that we run affiliate ads from Amazon. We do run affiliate ads from Amazon and have for about 5 years. There is a common perception that these pay meaningful amounts. In our experience it doesn't pay well at all. We still run them but if that is all you run on your site you would earn nearly nothing. Affiliate programs only pay when someone buys a product vs. our brand ads which pay for views.
The hard truth about online advertising is that you need millions of ad views per month, and they need to be mostly from North America or the biggest European economies, before you are earning meaningful payouts. If you are much less than that then you must have realistic expectations or you will always be disappointed.
If you have any further questions about what is WordAds or your specific earnings please don't hesitate to get in touch with me at firstname.lastname@example.org. Jon