Previews Hide Adsense but Show OTHER types of JavaScript Ads

[mhansen]

My question may belong in a different forum, please move if needed. Part technical questions, part observational.

The observation and issue.

When performing a bit of research this am, I decided to look at the "Preview" function in Google SERPS (The little magnifying glass) and preview the sites before I actually clicked through. I was specifically looking to exclude clicking on websites that had adsense blocks in the top-half of the resulting pages.

After following a few serp links, I found that the resulting pages, even though not showing in the previews, did in fact have adsense above the fold, some of them had 3-4 blocks, and I had to scroll to actually reach the content, which defeated my main purpose. I was trying to avoid SPAM signals and got the opposite.

When I returned to Google serps and looked through the previews, I noticed that Google does not show the adsense block in its previews. It completely collapses the area... making it appear as if the site is all content, no ads.

When I changed the search terms to preview a query that would include sites that are mine, or my own responsibility, I noticed that my own javascript embedded ad blocks showed in the preview, clear as day.

After several other queries, I noticed that Google is hiding its own ads from the previews, but showing others, which leads me to...

Questions:

- How are Google able to hide their own ad blocks from the SERP previews? I assumed they used Javascript and thus its not indexed (I do realize that javascript is capable of being indexed). If that is true, why are our site banners, which are embedded within "same-domain" javascript codes showing, versus being collapsed like Google ads? Is it because we serve from our own ad manager?

- Do you feel that ad banners being shown in the Google preview can affect your CTR? Pro's Cons, etc?

- Is there a way to selectively obscure banners from the preview tool? (Like, show free shipping banners, but hide banners that lead to offsite partners)

- Does anyone Optimize for the Preview tool, and if so, what extra steps might you suggest for encouraging click-through?

MH

[dstiles]

I thought the preview "tool" aka preview bot only went visiting a web site if the result wasn't already completely in google database as obtained by googlebot. Eg if images are prohibited to SE bots (which most of my sites are so I get preview bots visiting...).

If that is true then it's going to be difficult to inhibit ads from google unless you detect ALL bots and refuse them the adverts (if robot then block advert).

[agent_x]

I've seen the previews do some odd things. I had a site with a header at the top of the page consisting of a div with a fixed size, with a background image, and white text overlaid over the (dark) image. Unfortunately I ommitted to set the background color of the div to black, so the Google preview must have thought I had white text on a white background despite the dark image, and therefore didn't bother rendering the header at all. I only figured out this after viewing it in WMT. Could there be a similar reason why it doesn't render adsense on pages but does render other ads?