The scammers on Craigslist’s rental boards may finally be winning (and why that may be good for us all)

If you ever feel like Craigslist rental ads are really just a honey pot for spammers, unfortunately my data suggests you’re mostly right. My personal experience and friends’ anecdotes indicates it’s getting worse, too.

I’m in the market for an apartment in San Francisco (sigh). Over the past week, I’ve sent 20 emails in response to ads on Craigslist. I used a unique email alias for each listing.

I’ve received three legitimate responses in three days. Six have yet to go unanswered. A full 11, or 55% of these email address, have already received spam, presumably sold on the black market. This isn’t a statistically significant sample nor are these results scientific, but I do believe they are directionally correct.

The scam to harvest email addresses is easy enough. In fact it’s free.

  1. First, copy an old listing for a legitimate apartment, lower the price a bit and maybe add an amenity or two to make it attractive.
  2. Then set up an email address with an auto-responder asking for the applicant’s direct email address since Craigslist anonymizes email addresses by default . Generally these emails have a little more information about the unit. The best mention another interested party to create a sense of urgency.
  3. It’s easy to scrape email addresses from any responses that come in with trivial programming or manually with copy+paste.

Unfortunately, this is exactly what legitimate owners and agents do, too. And since you want a place to live, you have no choice but to become a coin in some spam king’s purse. It’s a little tax on every legitimate transaction.

On the surface, a few spam emails to put a roof over your head may not seem to matter in the long run and some inquiries will be ignored. However, in a market like San Francisco — where apartments rent in days and renters typically have roughly a two-week window to find an apartment, sign a lease and move in — dealing with a response rate of 15% is a real problem. The fact that the market still relies on Craigslist despite of this is a testament to Metcalfe’s Law.

I don’t think Craigslist is complicit in this but given their near monopoly motivation must be called into question. Any transparency or feedback system needed to ameliorate the problem would run counter to the stateless anonymity that that built Craigslist. I can hear product leads arguing that it would alienate their user base. But alienation is exactly what these illegitimate users need.

No one sober looks at Craigslist and thinks, “This is the product we need for the rental market.” So maybe this is the virus that is needed to kill the host so that something else can prosper.