Like many other NFL teams, the Baltimore Ravens are worried about the thousands of empty seats in their stadium.

Despite having a previous history of selling out each game since the team moved from Cleveland, the Ravens were suddenly forced to take out advertisements to induce fans to buy tickets at much-reduced prices.

The team has a long history of sold-out seasons at M&T Bank Stadium, but last week, as Week 13 began, the Ravens were seen taking out advertisements touting cheaper tickets with a campaign saying “Win Together. Purchase your tickets today,” according to the Baltimore Sun.

But, the campaign may be a tough sell as fans have already been trying to unload the tickets they already have for as low as $29 on Ticketmaster, eBay or other secondary markets.

According to the Sun:

“The Ravens are finding themselves in the same situation as a lot of NFL teams this year,” said T.J. Brightman, president of A. Bright Idea, a public relations and marketing firm with offices in Bel Air and California. “There is a disengagement by fans across the country stemming from the daily and weekly stories the NFL league office confronts.”

Indeed, photos of empty seats in Baltimore have crowded social media all season. And Sunday’s game was no different:

A large photo from last month is also amazing for the number of empty seats visible in M&T Bank Stadium.

According to the Sun’s Jeff Barker, the team launched the ad campaign in hopes of inflating ticket prices on the secondary market to “help fans” sell their tickets. But the team’s vice president for ticket sales and operations, Baker Koppelman, also admitted that the ad campaign was unusual.

Koppelman told the paper, “it is relatively new for us to advertise or promote ticket sales when we’ve sold out every game in our history.”

The constant player protests during the playing of the national anthem have also vexed the team’s front office. In September administrators hastily canceled a pep rally after retired linebacker Ray Lewis announced his support of the player protests during the anthem.

Despite the current issues, though, the Ravens still enjoy a high rate of returning season ticket holders and have a waiting list of up to 2,500 fans for the few season ticket seats that come up on the market. But diehard fans like those don’t seem to be indicative of most others. The team was even beset with the lowest TV ratings of the year for Monday Night Football last week with a low 6.0 in metered markets.

Follow Warner Todd Huston on Twitter @warnerthuston.