Royal Caribbean International would like the chatter surrounding the Oasis of the Seas to focus on its seven neighborhoods, nine-deck-high zipline and diving shows.

Instead, Royal Caribbean executives last week found themselves explaining and defending a seldom-discussed aspect of the cruise business: the revenue management system used to determine ticket prices.

In the case of the Oasis, it is a system that must be applied to 5,400 lower berths in 37 cabin categories on a weekly basis.

The selling of the Oasis became the subject of recent speculation after Royal Caribbean announced that there was still space available on the ship’s December sailings, including its inaugural cruise on Dec. 5.

Consumer chat boards and blogs lit up, and even cable news shows chimed in with comments about how the Oasis, despite all the hype and hoopla about it as the world’s largest cruise ship, was not selling well. The implication was that its first sailings should have sold out.

Rather than let the public think that demand for the Oasis was failing to match its stature, Royal Caribbean executives responded to the buzz during the cruise line’s third-quarter earnings call on Nov. 3.

"Someone here described selling out this early as being ‘yield management malpractice,’ " Royal Caribbean Cruises Ltd. CEO Richard Fain told Wall Street analysts. "It is simply the way we operate. We would not want to be sold out."

He added that reports about upper-category accommodations on Oasis having sold out suggested that "we sold those cabins too cheaply. We should have held them longer."

Royal Caribbean CEO Adam Goldstein added: "It has always been our intention to carefully ratchet up [Oasis’] load factor. … With respect to the amount of capacity that is for sale, we are definitely protecting our pricing division, if you will, because we know the value proposition that exists here."

Goldstein added, "We are simply not prepared to engage in some of the discounting tactics that we see in the cruise space these days."

At $1.5 billion, the Oasis is the most expensive ship ever built. But it is debuting in a recession that has forced some of the steepest cruise price cuts since the aftermath of the 9/11 terror attacks.

Royal Caribbean executives have been stalwart about keeping Oasis prices high, even if it means sailing with a few empty cabins.

"It is possible that we will have a slightly lower load factor in the end than we might otherwise have had if we would be more aggressive to sell each last space that we had intended to sell," Goldstein said.

He added that the hoopla surrounding the Oasis until the ship’s first cruise, including live coverage on ABC’s "Good Morning America" on Nov. 20, could mitigate "that potential small deficit."

Wall Street analysts appreciate this and have noted the bump that both the Oasis and the new Solstice-class ships of Royal Caribbean’s sister brand, Celebrity Cruises, have given the company’s revenue.

"Our year-over-year positive net yield assumption is driven by … the premium mix of cabins on the newer Oasis-class Royal Caribbean International brand and Solstice class," said Wells Fargo equity analyst Tim Conder. "Investors don’t fully recognize the positive mix impact" of the newer ships.

So why all the concern that the Oasis isn’t selling well?

One answer, according to Steven Hattem, vice president of marketing for CruiseOne & Cruises Inc., is that "with the economic situation we have, with pricing so aggressive with other companies, and with the launch being during the first few weeks of December, a low-season time, any ship would have its challenges."

Hattem observed that like any ship, the Oasis has sold from the top down and the bottom up, and that there is a lot of availability in the middle, the ship’s balcony and oceanview cabins.

"On any ship, you always sit with those cabins in the middle," Hattem said.

He added: "I think their yield management department will try to find the sweet spots so they can sell it more across the board. … They will probably raise some pricing on the higher-end categories and reduce some pricing in the middle."

Stewart Chiron, president of Leisure Pros, said Oasis pricing had been flat until around late July of this year, when it jumped about 25% for the ship’s earliest sailings. He said that during the summer, none of the lower categories were available.

"Then in September, like an early Christmas present, lower-category cabins became available," Chiron said. "Pricing in the winter months is challenged, and all of the ships that were introduced last year weren’t sold out either: Eurodam, Carnival Splendor, Ruby Princess, Independence of the Seas and Celebrity Solstice."

Many travel agents have reported that the Oasis has sold well and that they appreciate the solid pricing that Royal Caribbean has maintained, especially since rock-bottom cruise prices cut deep into commissions.

Hattem said that Royal Caribbean officials "were pretty clear that they’d rather go out with some empty cabins than discount that ship; $1.5 billion is an unprecedented amount of money they need to get back on that investment. I think they don’t want to set a precedent by reducing the cost on that ship. I think they’re going to work hard."

He said that even if Oasis pricing was too high for some customers, it made other cruises enticing, like a week on the Freedom for $799 compared with $2,299 for the Oasis.

Many agents point to the newness factor as the reason the Oasis commands its prices.

"If passengers want the newest and flashiest ship available, it’s going to cost a premium," Chiron said.

And, Hattem added, "The features of the Oasis can’t be found on any other ship afloat. The excitement and media buzz surrounding the Oasis is also getting the attention of many new-to-cruise consumers, and we expect this to be great news for the overall cruise industry."

Beyond ticket prices, Royal Caribbean is banking on the Oasis to generate strong onboard revenue from its 37 bars and seven restaurants that carry surcharges.

Like any cruise line, Royal Caribbean has to balance carefully what is inclusive and what is not. Making it more delicate on the Oasis is that some agents say its prices approach luxury levels.

Vicki Freed, Royal Caribbean’s senior vice president of sales, said that most service charges help minimize waste and maintain quality.

She said accommodating guests who want to try amenities like the rock-climbing wall, zip-line and FlowRider is not a problem. "We don’t have a service charge there," she said.

At specialty restaurants, however, "in order to maintain the high quality of not only the food but also the experience, we need to limit the number of guests we serve at one time. A service charge helps control the traffic."

Freed added that service charges in those venues were a good value.

She pointed to the $25 per-person fee to eat in Royal Caribbean’s steakhouse, Chops Grille, asserting that "the value of the dining experience in terms of a land-based restaurant easily exceeds that service charge."

Hattem said that cruisers in today’s market expect to pay for such onboard extras.

"This is not new to Royal Caribbean," he said. "They have Ben and Jerry’s and Johnny Rockets, and you pay extra for those things. … Sometimes [cruise executives] put costs in place just to control the flow. If it were free, 5,000 people would all go at once."