Number of indexed pages dropped dramatically

[SinaKashani]

The number of indexed pages for my site was 1100 yesterday and today is 344

Anybody has any idea what can cause this.

Thank you

Sina

[MikeRoberts]

Have you seen any corresponding drops in traffic? Have you made any recent changes? Redirects, canonicals, site remodel, link restructuring, changed hosting, updated your CMS, etc. etc. It'll be a bit unlikely someone will come up with the correct reason without more information.

[SinaKashani]

Nothing has been change since yesterday.

I read the news about MyBlogGuest today. I don't know much about SEO but is it possible that these two related, if I had a link there

[MikeRoberts]

It is unlikely that having links from MyBlogGuest would cause a drop in indexed pages like that. Where are you seeing this drop in indexed pages? Is it being reported in Moz or Google Webmaster tools? Also, do you have Google Analytics set up for your site to check other metrics? A large drop in indexed pages does not necessarily mean something wrong (canonical tags, cleaning up duplicate content, reporting errors, noindex tags, etc. can all cause a drop in indexed pages).