Dear DCist: Someone told me that it’s actually good to leave the Express behind on the Metro because you’re passing the news on to somebody else. That’s a good thing, right? Or am I just keeping the train dirty?

This is a tough one. The dissemination of the news is very important. Although Express distributors can be vigilant in their passing out of the free-drop commuter publication, not everyone gets to see their tabloid-size paper because they’re busy reading their copy of the “DaVinci Code,” or the more traditional broadsheets like The New York Times, or the real Washington Post. (The Post publishes the Express, if you didn’t know.)

WMATA has been pretty clear about leftover items on the train: Take them with you. You’ve heard the announcements from train operators. It makes WMATA’s job easier cleaning trains so the agency can spend their time on better things, like basic maintenance and customer service training. And we all like trains that don’t derail and friendlier transit staffers.

And the folks over at Express would probably say that you’re best to take your newspaper off the train too, in the name of being a responsible corporate citizen. But circulation number crunchers may not share that sentiment. Some free-drop publications estimate second and third looks into their circulation figures. In the art of circulation auditing, it is a delicate dance. Higher circulation figures means a higher profile. And that can translate into greater ad revenue. (This year, the Express increased its circulation because of greater "customer acceptance" of the free drop. Its readership stands at nearly 230,000 readers, but its circulation is 175,000 readers.)

So do you help the Express or WMATA, or is there a way to lessen the burden on clean-up crews if you do leave the Express behind? Well maybe, if you are doing it strictly in the interest as a news disseminator.

Perhaps you can play the role of a crude newspaper reader blogger, judging whether there is any good content in that day’s issue of the Express and leave it beyond. You could even -- though fellow passengers may consider you more than a bit eccentric -- take a red pen, circle the interesting news item in the Eye Openers section and write a note saying: “Hey, you might enjoy this!” That way, the next person who is reading it will see that you are doing them a service, and not just littering.

There is an additional strategy to giving the Express a second or third readership life. Set yourself a littering limit. For instance, if you are a Red Line rider and are on a Glenmont-bound train, it doesn’t make sense to leave the paper behind at Judiciary Square in the morning, as ridership plummets once past Union Station. If you leave it, let’s say at Cleveland Park, there is still about a 20-minute shelf-life for that copy of the Express, all the way to Metro Center and maybe even Gallery Place, depending on the time of the morning rush.

But the threat there is, if the last person left it behind, why should you make job of WMATA’s cleaning crew any easier? You can see the careful line you walk here. Do you potentially help the Express or do you help WMATA keep a cleaner transit system? We think careful consideration is required here, and there is no good answer, though we of course lean in favor of cleaner train cars and stations. And anyway, we tend to favor the real Washington Post over its free drop.

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