Search using Page previews - why are some missing?

[raj1094]

Dear Webmaster,

When i Search for keyword in Google and selected the option "Page previews" under "Standard view" from Right Menu. Some site showing up with their site preview and some not. What will be the reason for a site not getting displayed here. Should we check for any On page SEO factors here.

[tedster]

It's a rather new feature (begun last November) and not a lot of study has been done - plus there's no official word from Google that I know of.

I can't see a pattern, that's for sure. I also can't see a pattern between decent previews and those that are there by ridiculous. This is a feature that need some serious tweaking, IMO. However, I doubt that there are any SEO implications of a missing preview image.

[aristotle]

The previews for one of my sites are blank images. At first I thought it might be caused by hotlink protection and/or blocking images in robots.txt. But I have another site with hotlink protection for which the previews are okay, so that apparently isn't the problem. I'm still trying to determine if blocking images with robots.txt could cause it. I wish Google would say something about this, because in my opinion it gives an unfair advantage to some sites over others.