If you searched the term Coin Drops you will find below an exhaustive explanation of the meaning:
Coin Drops is a term used when promoting a numismatic event by putting a valuable coin into circulation.
The coin is deliberately put into circulation for advertising and promotion purposes.
An example are some Coin Drop made for many years by the American numismatic association.
This practice is not seen favourably by many collectors who think it is mainly a waste of valuable coins.
From another point of view, making a Coin Drop, is an economical way to promote an event and gives excellent visibility throughout the numismatic landscape.