Older than 25min because it's close enough to 30min and people creating posts only to buy votes on it 2min later are not really buying exposure but trying to skim a profit without investing in steempower.
People are encouraged to make profit by attracting other's votes on your post folling the promoting.
BTW the max cost for promotion is now 10%.
To my opinion it doesn't work that paid upvotes give your post any promotion. This because there are to many people trying to do this. And if 1,000+ people try to get their posts trending, it doesn't help.
Recent calculations could prove that about 30% of the votes are paid for. So all those votes are not used as they should be.
There certainly isn't room for 1000 top trending posts but there are others tags.
Bidbots are only selling about 10 votes a day.
When will you be refunding ineligible posts?
The vote has been done in the next round, the message was updated and was supposed to be :
Thank you and sorry for the confusion.
No worries, and thank you for resolving the issue:)