Sometimes you just want some pizza. But you don’t want to miss even a second of your True Life marathon, and more importantly, you don’t have the funds on hand. You figure that your best chance for getting some pizza to appear in your life is to appeal to the Reddit community. Those people spend a lot of time at their computers, and they get you! So you post on the subreddit Random Acts of Pizza—a magical place where users fulfill one another’s wishes for a pie. But science says your plan for world laziness domination is not going to work. It’s just not a compelling story.

Researchers at Stanford recently published “How to Ask for a Favor: A Case Study on the Success of Altruistic Requests,” and behind that name are the more than 21,000 posts and related data that appeared on Random Acts of Pizza between December 2010 and September 2013. The researchers analyzed the language of the pizza requests, the histories of the users who posted them, data about which requests had been fulfilled, and the differences between requests that did and did not result in pizza.

As MIT Technology Review explains, the group used a common machine-learning algorithm to analyze the body of data. The group used 70 percent of the data to let the algorithm figure out which requests work and which don’t, and then turned it on the last 30 percent to see how accurate its predictions were. Seventy percent of the time, the algorithm correctly predicted which pizza requests had been fulfilled.

You may not be completely bowled over by those predictive powers, but this is some deep textual analysis. The researchers separated the posts into five different types of narratives: money, a job, being a student, family, and a “craving” category that often involves things like friends, parties, and/or drunken revelry.

And the researchers found that family, money, and job narratives improved the likelihood of pizza fulfillment, while the other categories were neutral or reduced the chance of success. Politeness (specifically expressions of gratitude), evidentiality (like including a photo), reciprocity (an indication that the poster would potentially give pizza to someone else at another time), sentiment, and length were other factors contributing to success.

Here’s an example of a request that worked:

My gf and I have hit some hard times with her losing her job and then unemployment as well for being physically unable to perform her job due to various hand injuries as a server in a restuarant. She is currently petitioning to have unemployment reinstated due to medical reasons for being unable to perform her job, but until then things are really tight and ANYTHING would help us out right now.

I’ve been both a giver and receiver in RAOP before and would certainly return the favor again when I am able to reciprocate. It took everything we have to pay rent today and some food would go a long ways towards making our next couple of days go by much better with some food.

And one that didn’t:

My friend is coming in town for the weekend and my friends and i are so excited because we haven’t seen him since junior high. we are going to a high school football game then to the dollar theater after and it would be so nice if someone fed us before we embarked :)



The post with more information and context, plus a more compelling personal story, is more likely to do well with the Reddit community than the post that seems shallow and doesn’t make the reader feel like the poster is a meaningful contributor to the Random Acts of Pizza community. You can see how an algorithm that knows how to ask for favors in a compelling way might be able to abuse its power. And likewise good ol’ humans could take these findings and use them to game Random Acts of Pizza, but that would be really crappy. Who could be so heartless when the site’s motto is “Restoring Faith in Humanity, One Slice at a Time”? Oh, right, it’s the Internet.