LOS ANGELES, California (CNN) -- Music fans who buy concert tickets during Live Nation's "No Service Fee Wednesday" may be surprised when they check their receipt and see some service fees were charged.

Concertgoers expecting service-free tickets during a Live Nation promotion may still find fees.

Live Nation's announcement for the promotion -- and stories based on their news release -- did not mention the concert promoter's narrow definition of a "service fee."

"Fans will still be asked to pay parking fees (usually $6) as well as in some cases facility fees and/or charity fees," Live Nation spokesman John Vlautin wrote in a reply to CNN's request for clarification.

Still, the promotion will save consumers several dollars on amphitheater lawn seats bought from 12:01 a.m. to 11:59 p.m. Wednesday.

Vlautin did not respond to CNN's question about why the promotion was called "No Service Fee Wednesday" if there were still fees added to the base cost of each ticket -- or why it was not disclosed in the announcement.

Service fees tacked on to ticket purchases -- averaging a third of the base price -- have long been a source of grumbling from concertgoers.

"People get a little ticked off when they think they're paying $20 for a ticket and as they progress along the various pages of the electronic transaction they see more fees added along the way," said Ray Waddell, who writes about live music tours for Billboard magazine.

When buying tickets online using a credit card, the buyer does not see the total charged -- with the added fees -- until after they've submitted the order. Live Nation discloses this in its "terms and conditions" statement:

"Live Nation Ticketing may assess a convenience charge on each ticket purchased and/or ordered for certain events."

The parking fee, which does not actually pay for a parking space, is on each ticket -- even if the fan doesn't drive to the show.

"We have always charged it this way to alleviate traffic issues that occur when the fee is taken at the lot entrance," Vlautin said.

A facility fee is "charged at some venues and goes to defray the cost of venue maintenance," he said.

Vlautin did not respond to CNN's request for a detailed list of service fees that will be waived during "No Service Fee Wednesday."

Live Nation only began selling tickets to its own concerts last year, just months before announcing plans to merge with Ticketmaster -- the world's largest ticket-seller. Before that, Live Nation promoted shows but had no infrastructure to sell tickets, and it contracted out to Ticketmaster or others to sell them.

The Ticketmaster-Live Nation merger plan has drawn criticism. The Justice Department launched an investigation of the proposed merger in February.

Neither Live Nation nor Ticketmaster executives would respond to questions about the merger. However, Ticketmaster CEO Irving Azoff did talk about it before a U.S. Senate subcommittee earlier this year.

"[The merger] will give us greater flexibility in how we promote, market and sell tickets to events. It will give us a pathway to alternative pricing and fee structures. And we will be better able to develop new and innovative products and services that enhance the fan experience and make all forms of entertainment more accessible to everyone."

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