In the instructions, point 8, 'For promote function, enter:' is showing twice, instead of one for promote and the other for move to top.
Also try to explain that the ID and secret will appear when you click over the link of the new service created, I was going mad trying to find out where to get those.
It would be very useful to add to plugin in next update a confirmation email sent to user, to let user knows about the purchases made and duration in case of promoted ad.
Very nice plugin, kudos.