No, Viewzi does not crawl your website. Instead, we use data from API's provided from search engines like Google, Yahoo, and Ask.com.
Viewzi uses it's own screenshotting technology to take a screenshot of pages on your website. The Viewzi screenshotter is only dispatched on demand when a view (on behalf of a user) requests it, via a search that returned your page(s) in the result set.
The Viewzi screenshotter is built upon the Mozilla Gecko rendering engine, and can be identified by this user agent string:
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b4pre) Gecko/2008022910 Viewzi/0.1
The Viewzi screenshotter is powered by Amazon's Elastic Compute Cloud (EC2) and will originate from a machine within:
compute-1.amazonaws.com
Once we take a screenshot of the page requested by the view we cache and store it for the next time it's requested. This means we aren't screenshotting your site every single time it's requested. Currently we maintain these shots for 30 days before refreshing.
Since Viewzi doesn't crawl your site like a traditional search engine does, robots.txt doesn't really apply to
the Viewzi Screenshotter.