I have a classifieds site and have large buttons in the header and I just put small buttons near the bottom of the page in a logical spot. Will this affect my analytics? Will I be able to see whether shares were from the big buttons up top or small buttons below? Other than visual redundancy, is there any reason not to have the buttons twice on the same page like this?
Unfortunately you won't be able to see which shares happened from which buttons, but by having more buttons on the page you'll likely get more sharing activity.