"I was very surprised to hear the news," Luepke told Reuters by phone from his home in Germany.
"I woke up this morning and had an email from Apple saying I had the 25 billionth download," he said. "In fact, I didn't quite believe it at first. It's a new feeling for me."
Luepke, who is currently studying for exams, said he came across the song at a disco last Saturday night.
He used the song-identification smartphone application Shazam to look up its name, after which he downloaded "Monkey Drums" the following evening.
Luepke, who will celebrate over a few beers with friends, said he is not sure how he will spend the gift certificate, but he is confident that his music and movie collection will grow.
Cupertino, Califoria-based Apple launched the iTunes store in April 2003 and has averaged about 15,000 songs downloaded each minute. The store has a catalog of more than 26 million songs in 119 countries.