Advertisement impressions / view counters and guest caching

[Makoto]

Something that occurred to me recently:

From what I can tell, if you utilize guest caching on an IPS community website, pages that are cached will not update the advertisement impression counter.

This could be an issue for communities that utilize guest caching and sell impression based advertisements or otherwise rely on impression limited adverts.

If there was a way to offer support for registering advertisement impressions on cached pages, I think this would be a useful addition.

I'm not sure if this would be as simple as calling \IPS\core\Advertisement::updateImpressions(); on cached pages or if more work would be required (I haven't tested this locally yet). I feel like it might not, as the Advertisement class may fetch a different advertisement than is displayed on the cached page and thus would update the wrong impression counter if you called it on a cached page.

So making this work may require at the least logging the advertisement used with the cached page output.

(Actually this brings up another question, are other view counters and such updated with guest caching enabled? I imagine they aren't either)