Caching of banners

Dear Monks,
I tend to load load of perlmonks pages a day and I really appreciate this site.
One thing however seems strange to me. Why won't the ad-banners be cached? Here at the perlmonks I usually see some 4 different banners (OK, only the VA Linux in the last few days) and they seem to get reloaded for every single page. It's an effect I don't see at the (german) Heise Newsticker for example.
It's just fine to have some kind of banner lurking around but it's simply a waste of bandwidth when they don't get cached (which doesn't disturb me at all at work with the DSL connection and all, but at home with the good ol' Analogus Modemsus).

Am I completely nuts and is this behaviour just an error of mine er what?

Regards
Stefan K

$dom = "skamphausen.de";   ##   May The Open Source Be With You!
$Mail = "mail@$dom;  $Url = "http://www.$dom";
[download]

Comment on Caching of banners Download Code

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Re: Caching of banners by extremely (Priest) on Feb 12, 2001 at 21:47 UTC
The method used to move banners on this page is a script called "servfu.pl". If they set the headers so that your browser would cache the image, you would never see different banners. Some places use their own banner system that is integrated with their template system and can insert random images with associated links into any page and make them permanent images with real names. -- $you = new YOU; honk() if $you->love(perl)	[reply]
Re: Caching of banners by turnstep (Parson) on Feb 12, 2001 at 22:15 UTC
As to why they do this, remember that caching is good for you, but bad for the advertisers. There are many tricks used by sites to encourage "cache-busting." This is not a bad thing, but simply a reality - the site wants you to download (and hopefully view :) as many banners as possible. More pageviews = more $$$ from the advertisers. If it really bothers you (even if just from one slow location) you could install the Internet Junkbuster software, which lets you selectively block banners (along with lots of other useful features, e.g. cookie control) If you do go that route, buy something from the Buy Stuff page to appease your guilty conscious. :)	[reply]
Re: Re: Caching of banners by stefan k (Curate) on Feb 12, 2001 at 22:24 UTC
Actually I consider it OK if sites like this collect $$s by ads. Therefore it's OK for me to see the banners. But don't they count the requests and click-thrus and not the actual downloads? As far as I understand a cached banner would still cause a request for that banner and therefore provide some more $$ (process-numbers?? no, really dollars ;-) Just thinking.... Regards Stefan K `$dom = "skamphausen.de"; ## May The Open Source Be With You! $Mail = "mail@$dom; $Url = "http://www.$dom";` [download]	[reply] [d/l]
Re: Re: Re: Caching of banners by turnstep (Parson) on Feb 13, 2001 at 02:48 UTC
If the image is cached, then when you call up another page (or refresh the same page) that has that image on it, your browser is going to say "Hrmmm...'AnnoyingAd.gif'? I've got that in my cache, so no need to go out on the network and get it!" So multiple pages = one image download. Pageviews and click-throughs are both counted. The latter is much more desired, but the reality is that it is still usually around 1% or less of the pageviews.	[reply]
Re: Caching of banners by tadman (Prior) on Feb 13, 2001 at 05:54 UTC
The technical reason for them not being cached is that the URL of the image changes on every page. Your browser, and any cache software, such as Squid checks for cache hits by checking for an exact URL match. A change of 1 character in the URL is interpreted as a miss and forces a re-fetch. The URL is changed intentionally so that many different ads can appear on the same page, and also to increase the number of ads you can see, which should be about one per page viewed. PerlMonks banner advertisments are regular <IMG>s, but the source appears to have random content appended to the end. Here's a quick sample of the URLs for the banner ad which I compiled just clicking around: http://206.170.14.74/~adfu/servfu.pl?i,620,8885773 http://206.170.14.74/~adfu/servfu.pl?i,605,9795773 http://206.170.14.74/~adfu/servfu.pl?i,605,3711452 http://206.170.14.74/~adfu/servfu.pl?i,605,7281988	[reply]