WASHINGTON -- The attorney general for Washington, D.C., sued StubHub on Wednesday, accusing the ticket resale platform of advertising deceptively low prices and then ramping up prices with extra fees.

The practice known as ā€œdrip pricingā€ violates consumer protection laws in the nationā€™s capital, Attorney General Brian Schwalb said.

ā€œStubHub intentionally hides the true price to boost profits at its customersā€™ expense,ā€ he said in a statement.

The company did not immediately respond to an email seeking comment.

The mandatory ā€œfulfillment and serviceā€ fees are hidden until the end of a lengthy online purchasing process that often requires more than a dozen pages to complete as a countdown timer creates a sense of urgency, Schwalb said.

That makes it ā€œnearly impossibleā€ for buyers to know the true cost of a ticket and compare to find the best price, he said. Fees vary widely and can total more than 40% of the advertised ticket price, the lawsuit alleges.

StubHub is one of the worldā€™s largest resale platforms for tickets to sports, concerts, and other live events.

Sally Greenberg, CEO of the nonprofit advocacy group National Consumers League, applauded the lawsuit. ā€œHidden fees in the ticketing industry have truly gotten out of control. The price that is advertised is the price that we should pay ā€” full stop,ā€ she said. Ticket fees were also part of a sweeping antitrust lawsuit the Justice Department filed against Ticketmaster and its parent company in May.

StubHub used to advertise the ā€œall-inā€ cost of a ticket about a decade ago, but changed after finding that people are more likely to buy tickets at higher prices with the ā€œdrip pricingā€ model, he said.

Washington residentsā€™ per-capita spending on live entertainment outpaces that of many other major U.S. cities and since 2015, StubHub has sold nearly five million tickets in Washington and reaped about US$118 million in fees, the suit states.

The lawsuit seeks damages and to block the pricing practices. Schwalb settled another lawsuit last year with the Washington Commanders over fansā€™ season ticket deposit money.