Just a quick post for any Nikon users who are considering leaving iStock. If you are going to go back through your portfolio adding keywords to the metadata then don't use CNX to do this - use Photoshop instead. The reason for this is that CNX adds the keywords in reverse order, which means that the most useful keywords are then at the bottom of the list. If you become a contributor on Fototlia you will find that they rank keywords by importance starting at the top of the list. If you have used CNX then these will be the ones that occurred to you last ie 'colour', 'photo', 'horizontal' etc, rather than 'Christmas', 'Santa', 'presents' or whatever.
There have also been a few occasions using CNX when it has failed to save my keywords and I have had to start all over again. I think this is something to do with CNX saving them to a separate (invisible) file whereas Photoshop marries them to the original image. Or something. I don't really know, I just know it is not a good idea! All the best and Merry Christmas to you all.