When the Clinton Bush Haiti Fund was started in 2010, one of its first tasks was to give people a way to donate online.
It quickly put up a form, then over three days, it took steps that encouraged people to use the form to give far more. The fund changed the page layout, put new words on buttons, tweaked the page’s font size, and reduced the amount of information it required donors to provide. Those small changes helped raise an additional $1-million over the following month, an improvement of 10.2 percent in dollars per page view.
“As soon as we found out what was working and what wasn’t, we would iterate and keep moving,” says Dan Siroker, co-founder of testing-software company Optimizely, who helped the Haiti fund and worked in a similar role in President Obama’s 2008 campaign.
The process the fund and other organizations used to figure out what makes a difference to donors is called A/B testing, or variant testing, which pits two slightly different pieces of content against each other—be it a home page, donation form, advertising, or e-mail subject line—to see which performs better.
Below, see how Mr. Siroker found the combination of elements that performed best to raise money for the Haiti fund.
Learn more: Tests Help Nonprofits Increase Web Gifts and Improve Online Results




