Draupnir, the best way to find out is to do A/B testing. Use a script to serve an image ad 50% of the time and a text ad 50% of the time. Put each in its own channel. Then monitor the results. Personally I haven't found a big difference between the two, but it may be different for different sites.

Super Simple "coin flip" code for PHP:

if (rand(0,1)) // Randomly alternate between text and text/image ads. 
{ 
     // code for displaying text ads goes here 
} 
else 
{ 
     // code for displaying text/image ads goes here 
}

Do you know if there is a script for html pages ?
If so, is it easy for an old fart like me to understand ?
Thank you

It depends on your webhost's setup. Some may have the ability to tell the webserver to parse .html files looking for PHP before they serve the page.

Others might have the ability for the webserver to parse .html files as if they were .shtml files, looking for something called "Server Side Includes".

Either would require lengthy explanations.

Does your webhost have a support forum?

Lame_Wolf, not for HTML unless you are parsing it like Ron said. By the way, thanks for the code Ron ;)

You can do the same exact thing in the web page using javascript without messing around with server side scripts, PHP, none of that noise.

Something like this places in the HTML source should work just fine:

<script type="text/javascript">
var randnum=Math.floor(Math.random()*2);

if( randnum==1 ) {

// code for displaying text ads goes here

} else {

// code for displaying text/image ads goes here

}
</script>

Additionally, you can use banner ad rotation scripts and services to accomplish the same task.

[edited by: incrediBILL at 6:05 pm (utc) on June 5, 2009]

Thanks for the variety of methods to do this guys, going to try one out now.

Please report back

Bill,

Would you simply nest the entire google ad code right inside another bit of javascript?

Thanks

Yes, without the <script> </script> parts, just the stuff in between

Hmmm, how can you do that? The AdSense code that actually shows the ads is embedded in a script tag.

Here's my AdSense adcode as generated by Google:

<script type="text/javascript"><!--
google_ad_client = "pub-1111111111111";
google_ad_slot = "WWWWWWWWWWWWW";
google_ad_width = NNN;
google_ad_height = NNN;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>

So more than just removing the script tags (which I might do even though technically its against the rules to much with the code) I'd have to break up the code something like this? (Bold is original adcode)

<script type="text/javascript"><!--
var randnum=Math.floor(Math.random()*2);
if( randnum==1 ) {
// code for displaying text ads goes here
google_ad_client = "pub-11111111111111111111111";
google_ad_slot = "YYYYYYYYYYYYY";
google_ad_width = NNN;
google_ad_height = NNN;
} else {
// code for displaying text/image ads goes here
google_ad_client = "pub-111111111111111111111";
google_ad_slot = "ZZZZZZZZZZZZZ";
google_ad_width = NNN;
google_ad_height = NNN;
}
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>

I'm not sure I'm OK with doing this without the approval of someone at google... perhaps ASA could give a little guidance?

Also, if that were allowed, would they allow the more elegant:

<script type="text/javascript"><!--
var randnum=Math.floor(Math.random()*2);
google_ad_client = "pub-111111111111111111111";
google_ad_width = NNN;
google_ad_height = NNN;
if( randnum==1 ) {
// code for displaying text ads goes here
google_ad_slot = "YYYYYYYYYYYYY";
} else {
// code for displaying text/image ads goes here
google_ad_slot = "ZZZZZZZZZZZZZ";
}
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>

See, it gets into a whole can of worms if they start to allow it. What are they going to do, inspect everyone's code for logic errors?

[edited by: RonS at 9:16 pm (utc) on June 6, 2009]

Maybe a bit old:
[adsense.blogspot.com...]
But I think it's still relevant. And I've never seen anything from Google disallowing this kind of A/B testing.

Well, that's the definitive answer! They specifically will allow the approach of the first of my two examples, and warn against making any other change to the code:

the JavaScript template below - it will rotate between the two ad units, showing each 50% of the time.

<script type="text/javascript">
var random_number = Math.random();
if (random_number < .5){
//your first ad unit code goes here
} else {
//your second ad unit code goes here
}
</script>
<script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script>

When using this template, remember to replace “//your first ad unit goes here” with your ad code inside the first set of <script></script> tags.

Keep in mind that generally, modifying your ad code is against AdSense program policies. However, we've checked with our policy folks and
they've given our publishers permission to modify the code for use with this specific script for the purposes of A/B testing.
Please be aware that the AdSense team isn't able to provide any support or troubleshooting help for this script or this sort of testing.

So you split the code into two pieces, placing the two sets of adcode in the if/else part, then use only a single instance of the javascript call at the end.

Brilliant for folks who don't program on the server side!

Thanks, Bddmed!

Sorry for the delay chaps. I've been out of town.
IIRC hostgator do have a forum, not that I have ever visited it. and IIRC I can have SSI, although I have never dabbled with them.

To RonS : I use the old code, but I guess it will be the same.

[edited by: Lame_Wolf at 10:41 pm (utc) on June 7, 2009]

Again, thanks alot for the replies, this topic turned out better than I expected.

The site I mentioned hasn't gone live yet, but after ab testing a few of the ideas I asked about I will let everyone know how it went!

the JavaScript template below - it will rotate between the two ad units, showing each 50% of the time.

Is there a way of showing one set of adverts between certain hours of the day.

For example...
12am to 12pm shows adverts for account #1
12.01pm to 11.59 am shows adverts for account #2

(html pages)