Does online reflect your offline coverage?

If you capture the online version of a publication are you getting the full (printed) picture? Most newspapers and publications now have an online version of their coverage but if you use this as a proxy to what is out there, how representative is that?

I conducted a rather unscientific analysis and found that over the last 2 months there were 306 printed references to some brand names in a small selection of the printed trade press. Meanwhile, in the same period, there were 204 equivalent brand references from their online versions(thanks to Brandwatch). So online you don't get the full story? I would be very interested in your thoughts and experiences.