"In fact," says Chris Cloete, co-owner of the Chas Everitt International Franchise in Cape Town's northern suburbs, "having several agents trying to sell your home at once will very likely both lengthen the time it takes to sell, and lower the sale price.

"And this applies whether you award a so-called open mandate to several different agencies, or whether you award a multiple-listing mandate to one agency which then shares your listing with other agencies in its multiple listing group."

Either way, he says, the competing agents all know there is a good chance that someone else will do the deal and claim the commission, so most will not put much effort or energy into advertising and marketing your home properly.

This means it will take longer to sell and that there is a good chance of it becoming over-exposed to the market.

Agents who come along and sign you up on a multiple-listing mandate, says Cloete, are thus not doing you any favours. "Actually, I'll go further and say that the only person really likely to benefit from that arrangement is the listing agent — who gets a percentage of the commission on whatever they list, no matter what the eventual sale price is. Their primary motivation is thus not to market your property, but to be the first to list it."

In the case of an open mandate, Cloete says, the seller faces the additional risk of a "double commission" claim that could severely affect the profitability of his sale. "Such claims," he explains, "can easily arise when the eventual buyer of a property has viewed it with one agent and concluded the sale through another who is not too scrupulous."

Cloete also says that because there are so many agencies working in each area at the moment, there is vicious competition between some agencies to secure mandates, resulting in some agents intentionally overestimating the value of houses.

Don't be swayed by promise of riches
"The owner is flattered by the high prices suggested and, flush with the prospect of making a handsome profit on the sale of his most important asset, he then often makes the mistake of granting a mandate to the agent who gave the highest selling price estimate.

"Several months down the line, when the house hasn't sold, the homeowner may start to question whether the asking price was sensible. By this stage, the mandated agent may well have invited other agencies in to sell the property on a multiple-listing basis, and made the owner put up with numerous show days. The owner may even have turned down several offers that did not meet his asking price, but were actually quite realistic.

"Remember, by the time a buyer makes any offer, he has usually gone through the process of visiting many other properties, and has a pretty good idea of what constitutes good value in the area he is considering.

"Anyway, after the property has been on the market for two or three months, everyone who might have been interested in it has already seen it, and dismissed it. At this stage, even if the price then drops (which it inevitably does), the excitement has been lost, and buyers are reluctant to reconsider 'shop-soiled' goods.

"By now the seller — who may not have been desperate to sell at the beginning of the process — is probably exhausted with the selling process, and is ripe to be beaten down by the mandated agent to accept a lower than market-related price."

In short, Cloete says, awarding a mandate is not a matter to be taken lightly. "Home sellers need to consider it seriously, take the time to select the right agency and then award a sole mandate — a contract which has been proven time and again to deliver the best outcome."