Ask any real estate agent with their own Web page if it has helped increase their business, and the answer is almost always yes. If you ask the same agents if the work and costs involved in maintaining their sites are also on the rise, the answer again is likely to be affirmative.

While Massachusetts Realtors say they have no problem committing extra resources to a marketing tool like the Internet that brings results, more are finding themselves exercising extra caution in the face of increasing solicitations from companies that promise to deliver Web site traffic – for a fee.

Steve Levine, a Realtor with RE/MAX First Choice in Northborough, said he receives calls almost daily from Internet companies that want him to pay to set up a link from their site to his Web page, www.shrewsbury-ma.com.

There’s a million of these companies out there, he said. Everyone thinks they can make a homepage, and separate areas geographically, then call you and say ‘For a hundred dollars a month, you can have the exclusive link in your area.’

Of course you’re going to have the exclusive listing; you’re the only one they’ve been able to get to sign up for the service, he continued. Their Web sites don’t generate the hits for your page anyway. You’re better off going to a search engine and listing for free. When people go to look for real estate, they don’t go to those sites, they go to the general search engine.

Jay Burnham, an associate vice president with DeWolfe in Beverly who runs the Web site www.northshorerealestate.com, said there are sites that have proven to be effective in directing people to Web sites, but costs can quickly add up for people signing up for all of these services.

I’m amazed at how much money goes out, Burnham said after adding up his Internet-related expenses. I do almost all of the work myself, and my costs run between $4,000 and $6,000 a year, he said. That’s a lot for one agent.

Burnham maintains an enhanced site on Realtor.com which costs him about $300 a year, he said. Other expenses included subscriptions to property search engines for his clients that run about $100 a month and memberships in organizations like the Real Estate Cyber Space Society. Add those fees to costs for listing your site on certain Web pages, and costs can quickly spiral out of control.

There are some sites that charge you $10 per town per year to have you listed. If you cover a large area and you start getting into those sites, the cost adds up, he said.

I’m sure some of the sites are good; you have to ask yourself if it’s worth all money, said John Cotton of Cotton Real Estate in Osterville, who runs the Web site www.cottonre.com. Cotton, who has been in real estate for 26 years and running his Web site for about the last five years, said he receives solicitations on an almost-daily basis as well. We’ve tried some of them, like Boston.com and Realtor.com, he said.

However, Cotton said the most effective tool to get customers to their site has been their own marketing. We measure our site carefully, he said. About 75 percent of our traffic comes straight from people typing in www.cottonre.com, and another 10 percent comes from people typing in www.cottonrealestate.com or other variations of the name we’ve registered that directs people to the site, because we didn’t want to take any chances.

We do a lot of marketing. We put our Web address on everything, he said, adding that his site draws an average of 493 users daily who stay on the site for an average of more than six minutes each.

Filtering through all of the offers presented by Web companies takes a lot of effort, but is something that has to be done when almost half of your business comes from the Internet, according to Mal Duane of RE/MAX Realty Assoc. in Framingham, who runs www.malduane.com.

The Web site takes about 50 percent of our marketing budget, said Duane, who also has an administrator who spends at least four hours a day working with the Web page, but it produces 40 to 50 percent of our business as well. Duane said about 40 percent of her Web site’s users are people who were already familiar with her, but 60 percent are new clients who are finding malduane.com.

Carefully choosing where to spend your money and finding out which sites are most effective is key, she said.

I maintain about half a dozen links. I own the ZIP codes for Framingham and Ashland on RealEstate.com, I’m listed on HomeGain.com and I have a full site on Realtor.com, said Duane, who estimates she received about two offers each week to buy a link on a real estate Web site.

It can be excessive. I really have to decipher it and decide if it is worth my money. A lot of these sites don’t have any strength to direct traffic to your site, she said.

Before committing to paying for a link on any site, Cotton suggested asking that site’s operators to provide statistics about traffic.

Everything is measurable, he said. There’s no hiding. Ask for hard numbers. Have them show you what they’ve got.

I log into the site and check them out, Burnham said. If I go in and there’s only one other broker listed, I know it’s not a very good site. But if there are 50 or 60 other brokers there, and they’re people I know and respect, then I’ll be more likely to partner with the site.

Levine said Realtors who have established themselves in their market usually don’t need to rely on real estate link sites because they are already well-known in their community. But the Realtors who don’t do a lot of business yet could fall victim to it, he said.

The Realtors interviewed also said industry professionals need to be cautious of Web-based companies that direct traffic to Internet sites in exchange for a referral fee if a property is sold.

Levine said companies will flood a search engine with doorway pages and offer to send people relocation packages, then collect a sizeable referral fee if the person ends up buying a home. They’ll set up pages for towns everywhere, even though they know nothing about the town and are based somewhere like Baton Rouge, he said. It’s still a big problem, though it’s not as big as it used to be.

According to Levine, referral Web sites are not as prolific in the Boston area and other major cities where several real estate agents and companies already have established Web sites. But when you get outside of the cities, in places like rural Iowa, it’s worse, he said.

And here’s something else with referral sites, Burnham said. If a buyer happens to browse around and register at three different referral sites and ends up buying a house, who do you owe [the referral fee]? Do you owe all three? What if they all demand it?

Burnham added that he has not encountered a situation like the one he described, but said it is something that needs to be considered when dealing with referral Web sites. I’m with DeWolfe, so I’m lucky because it’s a big company with relocation services so I get referrals from there, he said.

[The referral sites] also give the buyers anonymity, Burnham continued. How does that help us? We do all the work with the chance that we’re never going to meet the guy. That’s another reason I’ve stayed away from them. In addition to companies solely in business for relocation, now you’ve got painters, contractors, everyone trying to get a piece of it. Everyone hopes they can get a piece of the action, and I’m sure they do, but I’m not in favor of that at all, he said.

Cotton said real estate agents and customers need to exercise caution when working with companies on the Internet just as they would any other business. People think that because it’s on the Internet, they can suspend all reason, he said.