It means that someone/s typed in "www.domino.co.uk" 309 times in Nov 2005 into the search bar of yahoo.co.uk, msn.co.uk, ask.co.uk plus some other search engines but not google.co.uk. ie, the ones that Overture quotes in its blurb. [Btw, 309 is pretty good.]
This can be taken as an indication of how many people may have typed "www.domino.co.uk" into the address bar of their browser, assuming that those typing it into the search bar may have intended to have typed it into the address bar.
This is then an indication of the amount of direct "type in" traffic that a domain name gets .... the higher the number, the more valuable the domain .. in theory.
Watch out for hyphens.... the OV results can be misleading for hyphens. It seems that people quite often type in separate words, no hyphens in between and on the last word they stick on .co.uk ... I've wasted a few reg fees finding this out
Have fun finding high OV rating domain names ... many people spend too many hours searching for the illusive one that will make a bit of money :???:
EDIT:
I take too long typing ... good reply above!