KFC says Americans are gobbling down so many Double Down sandwiches that the fast-food chain will offer the bunless, meaty sandwich longer than it had planned…

The Double Down came onto the market on April 12 and was supposed to have lasted about six weeks. But it tapped into Americans’ fascination with quirky food and became a viral-marketing sensation. People posted videos of themselves eating the sandwich on sites like YouTube, and celebrities like Stephen Colbert gobbled it up.

KFC said it has been one of its most successful sandwich launches ever. Later this month, KFC expects to sell its 10 millionth Double Down. They cost about $5.