I definitely abandon more books since I switched to ereading. Not just freebies too, also books that aren't in my preferred genres that I've just not been able to get into, Kurt Vonnegut, Stuart MacBride & Dean Koontz (the latter two whose books I normally read and enjoy) have been abandoned and marked with a big red angry cross in Calibre to signify that they NOT FINISHED! I don't really like not finishing books
Kobo certainly knows nothing about the few books I've bought from them as they are converted to be read on my Paperwhite. Most of my Amazon purchases are 'cleaned' and sideloaded and then deleted without syncing to Amazon's servers so not sure how much info even Amazon would have?