Sometimes ads appear, sometimes they don't. Why?

Why do my pages sometimes show ads, but then not?

[kb08807]

I have been using Adsense ads on my site for a few months now. I have selected PSA's to NOT show on my site. For awhile, my pages were always showing ads, really on-target for the topic of the article on the respective pages, so all was going good.

Now, more and more, I notice that I'm not seeing any ads on my pages. I'll check for example "page1.php" and not see any ads, then come back to it a couple hours later, see ads in all the spots, and then the next day, no ads show again. The content of the article on "page1.php" has not changed, and it contains no "red-flag" content (like nothing about gambling, etc.) (I don't think I would ever see ads on the page if there was any red-flag content.)

I can only assume that when I see that blank Adsense area on my page, it is because Adsense wanted to show a PSA and I have PSA's turned off. But why so many PSA's these days? Those exact same pages with the exact same content used to be showing really on-target ads every time I checked the page. But now, I'd say I only see ads 25% of the time on most of the pages throughout my site.

I don't know why this is happening. Why did I used to see ads just about every time a page loaded, and now I see less and less ads?

I don't get a whole lot of traffic on my site. Is this why? Like if I had more traffic, would Google start giving me more ads to display?

If anybody has any ideas, I would love to hear them. Thanks so much.

[IanCP]

The first thought that comes to me is a possible lack of ad inventory relevant to your pages.

Sometimes there are ads available, sometimes not.

[Jenstar]

If they are coming and going, I would also think it is a lack of inventory for the particular keyword combination AdSense is using to display ads on those particular pages.

Also consider a geotargeting issue - if you are in Canada but your audience is in the US, you might see PSAs frequently, but your US audience might hardly ever see one. You can view your site with a proxy to check.

If it was a stop-word ("Red-flag") issue, it would never show ads.

[FromRocky]

For a month now, we haven't heard of any off-targeted complaining. This means the ads now are more well-targeted than before. More well-targeted, less ads supplied for each site.

With less-targeted, each site will have more than 4 ads at any given time, so the ads will be shown all the time. In some certain industries, a site may have an average of a well-targeted ad as an example. So if one site shows three or four well-targeted ads, the other three sites have to show PSA's or nothing.

[kb08807]

Thank you all for your replies and insight. After reading your comments, it does make sense that Adsense-participating-site demand for those ads could be greater than the supply of Adwords-customers-paying-to-Google ads.

Maybe I'm in an over-saturated market, content-wise. (Maybe?)

I guess if Google has a choice between sending an ad to my site, and the same ad to a similar-topic site that gets higher traffic, Google is probably choosing to send to the higher traffic site. (At least that's what I would do, if I were Google, and wanted to make money.)

OK, well thanks to you all for your insight and good explanations. If you or anyone else reading this has anything else to add, please do. :-)

[ChrisKud5]

I have experienced this as of late as well. I am by no means in a category that suffers from a lack of available ads. I argue that my site topic has more ads available than any other topic.......or at least pretty close.

I had the alternate color for some on FFFFF for awhile, and i did not really like not seeing anything. I am not sure why the page cannot get targeted ads, it is just like 10,000+ pages i have that are well targeted.

Maybe they will figure the targeting out soon i hope