Yes @luceos, let me try to explain the problem. First of all you have to know that Google Adsense is very restrictive and if you don't follow its TOS strictly, you will find your account banned in less than a week.

When you add Adsense to website, you have to add Ad-units or in other words, rectangles that contains the advertising. You have to do it using javascript provided by Google Adsense, for example this one:

<script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>


<!-- responsive-rectangle-adunit-example -->
<ins class="adsbygoogle"
     style="display:block"
     data-ad-client="ca-pub-xxxxxxxxxxxxx"
     data-ad-slot="xxxxxxxxx"
     data-ad-format="auto"></ins>
<script>
(adsbygoogle = window.adsbygoogle || []).push({});
</script>

The code provided by Google Adsense can't be modified.

If we inject the code of an Ad-unit into a post (for example first post of a discussion), it will be showed only if the visitor see first post of the discussion.

Now we imagine that the discussion has 50 replies. The user scrolls down to reach reply number 50, but suddenly he decides to check again reply number one. In this process the Ad-unit inserted on first post is reloaded, and this is what Adsense doesn't allow, realoading ad-units.

Also the javascript code reads the contents of the webpage to serve related ads and i'm not sure if Adsense will be able to read this contents.

Anyway i'm not 100% sure that we are violating the Adsense TOS, because while we scroll the differente replies, the URL page also changes and i'm not sure if the adunit is cached (consequently does not reload).

But since we have no official info about this, simply want to know if someone tryed to use Adsense on discussion's replies. I fear Google bans.

Not sure if i explained properly but i will try to solve any questions.