Donation options offer a glimpse into campaign finances

Thinking about donating to a political campaign? What you give might depend on how you get to the website.

Presidential campaigns are just like any other business — they're trying their hardest to figure out how to get your money. And like most businesses, you can decide how much or how little to spend, or not to buy what they're selling at all.

Conveniently, most campaigns give you preset options on their website for how much money to donate. And the way a campaign structures its donation preset options can tell you a lot about how the campaign is run, and who they think their likely (financial) supporters are.

$25 $3 $10 $25 $10 $15 $10
$50 $5 $25 $50 $25 $27 $25
$100 $10 $50 $100 $50 $50 $50
$250 $25 $100 $250 $75 $100 $100
$1,000 $50 $250 $1,000 $100 $250 $250
$2,700 $100 $1,000 $2,700 $250 $500 $1,000
$5,400 $250 $1,000 $2,700

Three of the current campaigns include a $2,700 option on their main donation page, according to the campaigns' "main" donation page (some campaigns have different donation landing pages depending on whether you've given before or other factors). That's the max amount an individual can legally give to a campaign in one election cycle. (Of course, thanks to the Citizens United court decision, deep-pocketed donors have any number of workarounds to pump money into the political system.)

You can think of that $2,700 donation as a decoy to make the other amounts seem palatable. A lot of restaurants have one item on their menu that's way more expensive than everything else, but they don't actually expect you to order a $50 steak. It's called the anchor, and it's there to make that $15 bowl of spaghetti look more reasonable.

Ben Carson, whose campaign is on the ropes, has the highest amounts listed on his default donations page. The preset options start at $25 and go to $5,400, which is the total amount a couple can donate. A spokesman for the Carson campaign explained that the totals were determined through a series of A/B testing.

"We adjusted these totals for a number of months but finally landed on this set being the most effective for the largest segment of our donor file," he wrote in an email.

Carson had raised almost $58 million and spent nearly $54 million as of Jan. 31, according to the Federal Election Commission.

Hillary Clinton has the lowest preset amount, at $3. Her main donation page has seven options and goes up to $250. That's a lot less than her Democrat opponent, Bernie Sanders. He may be thought of as the populist choice, but his main donation page's lowest option is $15 and goes up to $1,000.

"The reason you see such disparate approaches across the current campaigns is because all of them are still testing and learning on the fly," said Jordan Cohen, chief marketing officer at Fluent, a consumer marketing and advertising technology firm that provides services to many political campaigns, including several of the top 2016 presidential candidates.

A detail of Hillary Clinton's website showing donation amounts on Super Tuesday, March 1, 2016.
Source: Hillary Clinton
A detail of Hillary Clinton's website showing donation amounts on Super Tuesday, March 1, 2016.

"There is also an element of what the campaign needs now and what the campaign thinks it can get away with asking for from its advocates that is driving what they are asking for," Cohen said. So as much as campaigns are relying on sophisticated algorithms to tailor their online message to the particular user, there's still some old-fashioned guess work and desperation at play.

When campaigns are staring into the abyss, they're more likely to try to pull in whatever they can in the hopes of staying alive. The day before Super Tuesday, the Carson campaign sent out an email asking for an "emergency donation."

"Right now, we don't have the resources we need to compete in all 12 of the states set to vote," the email read.

That same Carson "emergency donation" email included a link to a different donation page with lower amounts.

Repeat donors are likely to give more than first-timers, Cohen said. That could be why Clinton has another page set up that has donations starting at $25 and going up to the max of $2,700.

A spokesperson for the Clinton campaign did not respond to CNBC's request for comment.