the proxy you are using would be my guess. likely a way for them to generate revenue. just a guess on my part though.
I have bunches of Siri add ons and haven't gotten a single ad. What kinds of questions are you guys asking when it spams you? Also, since it appears you're using IMZDL, which server are you on, specifically?
Update: Problem solved! I emailed the developer of SpeakEvents and this was his response...
this ad is served by AssistantExtensions. If fact I wanted it to show only once a day and only on 2.3.2012. The problem is that even if it is remotely disabled, it shows when you open Siri in less than 30 seconds since respring and I am very sorry for that. AE update will fix it (I will remove ad support entirely).
To fix it now at your side, you can remove this file:
Sorry for inconvenience.
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