I know I am going to catch hell for this:

If the person wont leave you feedback after a little nudge,
Hey, I know you are probably busy or forgot but could you leave feedback for me at: ____LINKY______
Perhaps you can go back and edit your feedback for them to include this little nugget of information.

After requesting this person leave a feedback for the sale I waited another week and feedback was never added.
I know sometimes we all get busy, little things get overlooked.
Life gets a little busy with Diapers, Yuky nose, Cheerios, Daddy I want apple, Doctors appointments, interviews, family appointments, Wifey's Honey-do list... ARRGHH!