Two points: (1) this is U.S. traffic only --- more than half of our traffic is international (2) the slump corresponds with the seasonality of U.S. travelers; compare with vrbo.com for a similar example.
The author did not book the property through Airbnb. Had he done so, he would have learned what we do in these rare situations. His article missed a couple key points:
1) If a host cancels a reservation on a guest, a default review is generated stating that the host canceled X days before arrival. The guest can modify this auto-generated review if he wants to add color to it.
2) The host is penalized monetarily if he cancels on guests more than once per 90 days. The penalty is $100 if the cancellation is within one week of arrival, otherwise $50. Hosts that repeatedly cancel on guests may be removed from the site.
As a result of these policies, host cancellations are rare. Most occurrences are honest mistakes and not from repeat offenders.
We got the following message from an Airbnb user two days ago:
"I absolutely love your service and am actually considering using it as my primary dwelling place (instead of paying rent, telecommuting as a Ruby developer and traveling around the world)... This month I've been using jetBlue's All-you-can-jet pass, and AirBnB, to write a song in 12 different cities..."
I'm co-founder of www.airbnb.com, a website that let's you find locals with whom you can stay while spending less money and having more fun. Our coverage in Boston right now is relatively sparse, but there are some places you might like.