GameDaily has recently interviewed Heather Hawkins from STL Ocarina. Here is a portion that talks about Ocarina of Time's impact on sales:
"GD: How has The Legend of Zelda: Ocarina of Time impacted not only the ocarina's history, but also your business?
HH: A large number of our customers were introduced to the instrument by the Ocarina of Time, so we've had a lot of people coming to us specifically looking for a Zelda replica. Many find that they enjoy the ocarina so much that they start collecting other models as well. The ocarina becomes a relaxing hobby for them."
You can check out the rest of the article
here.