'Tis the season: The market's hot and sellers rule, but if you want to get the most for your house, don't be a Scrooge about the Multiple Listing Service.

REALTORS® critical of colleagues who entice buyers into bypassing what's considered residential real estate's most valuable marketing tool, are warning sellers not to be taken in by a market of multiple offers, fast sales and especially, fast-talking real estate agents who ought to find lumps of coal in their Christmas stockings.

"I am not talking about the difference between the for-sale-by-owner (FSBO) and those who elect to use a REALTOR. I am talking about the consumer who elects to have a REALTOR represent them, but unfortunately picks a REALTOR who is more concerned about his or her wallet than the consumer's wallet," said Richard Calhoun, broker of Creekside Realty in San Jose, CA.

The San Jose/Silicon Valley market of more than 1.6 million people, is so hot there are fewer than 750 homes for sale from among the area's 300,000 owner-occupied housing units.

In Silicon Valley and other hot markets, homes that sell within hours after they are listed create in consumers an overwhelming sense of power errant REALTORS prey upon with the exclusivity carrot, Calhoun says.

Not so, say other REALTORS. Some sellers have good reason to avoid the MLS.

"Certainly the home may have a relative market value of $270,000, but if the seller needs it sold yesterday for whatever reason (divorce, impending foreclosure, immediate relocation, a need to raise cash, closing on another home, etc), then it's foolhardy to hold out for absolute top-dollar," says Sharon Marsh a REALTOR with Coldwell Banker in Plano, TX.

Resale homes competing with new homes can also put sellers in a bind and make them consider the MLS alternative, "exclusive" or "pocket" listings that never show up on the MLS.

"Even here in North Texas where it's been a seller's market for quite a while now, we're starting to see neighborhoods where it's a completely different story and the sellers are in tight competition with new construction. When builders in those competing areas can offer deep buyer and agent incentives to get inventory off the books before taxes are due, it just makes good horse sense to list an existing home at an aggressive price if you need to sell quickly," Marsh said.

If homes sell so fast, sellers and their exclusive listing agents reason, why not reduce the hassle of the hordes of buyers an MLS listing will bring?

For that matter, why even bother to hire an agent and pay a commission when the agent likely won't even have time to work for it?

Why?

A higher selling price, say critics of exclusive listings.

Money.

Listing your home on the multiple listing service, even for a short while, exposes your home to all MLS-member real estate agents -- and their clients, consumers looking to buy a home.

Otherwise, you can leave tens of thousands of dollars of equity on the table.

"I can think of very few legitimate reasons for not putting a listing on the MLS. Examples might include serious illness in the family or extreme or embarrassing filth or messiness which the seller is incapable of curing," said Susan Tilling, a Menlo Park, CA-based broker associate with Coldwell Banker.

The MLS, considered a REALTOR's most valuable marketing tool, is a data base of homes for sale in a given community. Except for limited Internet access and the few public MLS systems, the vast majority of MLS systems are open only for listings from REALTORS and only REALTORS can see complete listings.

Today's computerized systems allow MLS operators to update the data base and broadcast its contents as fast as someone can type in the details of a new listing -- price, address, square footage, number and types of rooms, age, style amenities, telephone numbers of the listing agent, sales status and a host of other information about the property.

In the past, MLS systems were localized, though no less valuable. With today's Internet boost, and ever more automated search engines, virtually any REALTOR anywhere, tens of thousands of them, can know virtually the instant your home is for sale.

The equation is simple, say those who poo-poo exclusive listings: more exposure, means more buyers will see your listings. The more buyers vying for your home the more likely you'll get more than you are asking, especially in a tight market.

"Agents price properties using comparable data.Very few buyers will offer more than that asking without direct competition. Even full time professional agents cannot possibly know how high buyers will go," said Calhoun.

So why do some REALTORS suggest that sellers not use the MLS?

Again, money. Time too. Time is, after all, money.

A REALTORs prime motivation to take a listing exclusive is the commission, critics say. A single REALTOR gets it all if he or she also represents the buyer interested in the property. At the very least, the commission remains in house, as the REALTOR attempts to sell primarily to buyers represented by other agents within the listing REALTORs brokerage. Some brokerage's reward REALTORS for keeping listings in-house.

If the REALTOR sells in-house it also makes for more congenial negotiations with less hassle than with a tough outside competitor.

REALTORS also capitalize financially by turning exclusivity into a marketing tool to attract buyers with the I-get-'em-before-the-MLS-does pitch. Half a commission coming in more often can make exclusivity a cash cow. The draw for the seller is exclusive agent who also represents the buyer. That REALTOR can afford to offer the seller a reduced commission, an attractive marketing tool.

Of course, this all raises the dual agency question.

One agent representing both the buyer and the seller or two agents (one representing the buyer, the other representing the seller) from the same brokerage in a dual agency transaction poses the possibility of a conflict of interest no matter how much due diligence, fiduciary responsibility or ethical behavior promised.

"The greatest potential for the conflict of interest which dual agency may pose occurs when the very same person is both the listing agent and the (buyers agent). The potential conflict of interest is greatly diminished when two different persons are involved, even though they may work out of the same office or perhaps different offices of the same company," says Tilling.

"If sellers refuse to allow any offer to be brought by an agent from the same large company they list with, then anywhere from 20 to 50 percent of the agents with potential buyers may be prevented from showing it," she added.

So what's a seller to do? Exclusivity or not?

Paul Joseph Joyner, broker-owner of Sommers-Ethan Properties in Santa Clara, CA answers that question from a buyer's perspective, after an exclusive listing REALTOR told the buyer he could not buy the exclusive listing unless the exclusive listing REALTOR also served as the buyer's agent.

"Question the rationale of the agent. Get answers to your satisfaction. Remember also, there is nothing which precludes you as the buyer from knocking on the door of the seller to ask the seller if he or she is aware of what exclusivity means. You are one buyer who isn't getting a shot at the home. If the seller is aware, you should call the seller's own rationale into questions and be a wary consumer. Any situation in which you are denied representation by your own agent, is one not in your best interest," Joyner said.