No. I think there is less traffic by typing in manually but I like to do it that way because it gets me in under the radar when I am spa.......er.......advertising.It all depends on a range of factors, do you think you'll get a higher response rate if you have people click a link and do a double meta or type it in manually themselves?
Heh, depends what you mean by 'valid' - this is Blackhatworld.As for your original question, you shouldn't need to worry about impressions as long as your method of promotion is valid (might be best to talk to your affiliate manager about it).