Darren Criss' 'Teenage Dream' May Become Most Popular 'Glee' Single Ever

Estimated to sell between 150,000 and 175,000 copies on iTunes, the tunes may soon overtake Journey's "Don't Stop Believin'."

Glee’s cover of Katy Perry’s “Teenage Dream,” featuring guest star Darren Criss, is expected to sell between 150K to 175K downloads its first week on iTunes for the week ending Nov. 14, Billboard reports.

This would make it the best-ever sales week for a Glee single, trumping current topper “Don’t Stop Believin’” by Journey. "Don't Stop Believin'" sold 177K when it was released May 2009.

According to Columbia, which releases Glee's soundtracks and music, "Teenage Dream" sold more than 55K when it was released Tuesday, the highest first-day sales for a Glee track.

Criss is reportedly being promoted to series regular after his appearance in Tuesday’s episode, “Never Been Kissed.”