To avoid accusations of commercial blasphemy, I am going to pose this as a question, not a statement: can you over-monetize a data product?

Consider the online real estate listings databases. There are lots of them, all engaged in a fierce battle to the death. They make their money selling listing upgrades to real estate agents, a hotly competitive and demanding group. The product they are selling is homes that can easily cost $1 million and more, with very sizable commission dollars at stake. In such a high ticket and fiercely competitive market, would you want to junk up the user experience with irrelevant advertising, and annoy your real estate agent customers by distracting users from the listings they are paying to enhance? The answer appears to be yes.

Several of these sites have now been designed to display programmatic ads. With all it takes to attract a live buyer to your site, do you really want to risk that buyer clicking on an ad for a local car dealer and leaving your site entirely? Do you want to intersperse listings of homes with ads for mortgages when your primary source of revenue is real estate agents who badly want your site visitors to look at their listings?

You know the saying: real estate is all about “location, location, location.” Does it make sense then that when a potential buyer clicks on a map icon to see where a home is located, she is presented with a map cluttered with logos indicating the location of nearby State Farm insurance offices? Does anyone buy a house based on proximity to an insurance agent? Doubtless someone thought this was a clever marketing gambit, but it distracts, confuses and possibly annoys the potential buyer.

The photo slideshows that are the critical core of each home listing are now increasingly cluttered with advertising. If I was a real estate agent paying to upgrade a listing only to find it was chock full of ads, I’d be furious. I want prospects looking at pictures for the home I am selling, not distracted or annoyed by irrelevant advertising from third parties.

A lot of this comes down to the degradation of the user experience. But in some cases, it’s an even bigger issue: it’s a problem of the data publisher forgetting who they are serving and in some cases, why they are even in business. A little bit of incremental revenue can sometimes have a very high cost attached. And the guiding rule of all things online remains the same: just because you can, doesn’t mean you should.