It's only fitting that a team that has enjoyed one of the most shocking turnarounds in the NFL this season ended with another surprise.

The Cincinnati Bengals announced they have sold out Sunday's regular-season finale against the Baltimore Ravens, a day before the NFL's blackout deadline. The odds of filling up Paul Brown Stadium seemed extremely slim before the team used some creativity.

Cincinnati used a special promotion for season-ticket holders -- "buy one, get one free" -- to record its second sellout of the season. The Bengals can clinch their third postseason berth in two decades with a win over the Ravens.

"Our fans have made a tremendous response this week to our sales efforts, and we thank the entire community for its support of the Bengals," Katie Blackburn, the team's executive vice president, said in a statement. "We're pleased that the game will be on television for everyone, and we look forward to the fans at Paul Brown Stadium giving us a great home-field advantage for a very important game against Baltimore."

If the Bengals (9-6) can knock off the Ravens (11-4), Cincinnati would be headed to the playoffs and in search of its first postseason victory since the 1990 season. The Ravens need to win to clinch the AFC North title and a first-round bye. Baltimore could clinch the division even if it loses, but only if the Pittsburgh Steelers lose to the last-place Cleveland Browns.

The Bengals have been the unexpected success story of the division, going from a four-win 2010 season to playoff contention this year. But the team has struggled to sell out games and has played regularly at the 65,000-seat capacity Paul Brown Stadium with one-third of the seats empty.

The only sellout this season came against Pittsburgh, when a large contingent of Steelers fans made their way from Western Pennsylvania. Now, in order to have a true home-field advantage, Bengals fans must resist the temptation of selling their tickets to Ravens fans who will be coming to town.

Only 41,273 fans showed up on a sunny, 38-degree afternoon to watch Cincinnati's breakthrough 23-16 victory over Arizona on Saturday.

"It's a great thing," defensive lineman Domata Peko said of this week's sellout. "When everyone in 'The Jungle' gets up, standing and cheering, it's as loud as it gets. Hopefully the house is rocking this weekend and we'll put on a show for everybody."

The Bengals said some club seats and single seats were still available, but enough tickets have been sold to meet NFL requirements for lifting the local television blackout.

"Just to have everyone here in Cincinnati wanting to come out for this game, I think that's something we've been wanting and been trying to get for a while," quarterback Andy Dalton said. "I'm just happy everybody responded to it. It's going to be a fun atmosphere, and we're excited about it."

Jamison Hensley covers the AFC North for ESPN.com. Information from The Associated Press was used in this report.