I plan to add a new feature to simplify their job. Here is a brief description:
1. advertiser accesses AA via https, enters the captcha
2. AA generates unique PHP code for advertiser
3. advertiser embeds this code into his/her goal page
4. when visitor opens the goal page, this code will sign & send info about successful visit to anonymous ads
5. advertiser can access report of successful visits and reward affiliates for them
Later support for other (non-PHP) server platforms can be added.
The feature added in some simplified manner: AA doesn't generate unique PHP code for advertiser (it generates only RSA keypair). But there is
an explanation and simple PHP example. I also added some explanations
for affiliates and
for advertisers.
If you decide to embed goal tracking into your PHP site - please let me know, I can help you.
If you port it to some other language or make CMS module and don't mind publishing it - please let me know too

So, now theoretically advertisers have an easier way to track visitors' actions and reward affiliates. I hope it works on practice.