Democratic presidential candidate Bernie Sanders smiles as he arrives on stage for a rally at Key Arena on March 20, 2016 in Seattle. JASON REDMOND/AFP/Getty Images

The latest round of federal disclosure forms show that Bernie Sanders continues to dominate fundraising for this presidential campaign cycle, with a reported haul of more than $43 million in contributions over the course of February alone. His campaign's windfall once again dwarfed that of even the formidable Hillary Clinton fundraising machine, which reported a $30 million intake over the same period.

Those numbers should be especially welcome news for Sanders because of his marked disadvantage when it comes to media coverage. He needs to spend more than any other candidate just to get the same amount of "earned media," or free press attention. Even Ohio Gov. John Kasich, running a distant third in the Republican primary when it comes to pledged delegates, gets more bang for his buck.

Last week the New York Times, using data from media research firm mediaQuant, estimated the dollar value for free media attention that each presidential candidate has received so far. Unsurprisingly, Republican front-runner Donald Trump had a colossal lead over all the other candidates. He has received nearly $2 billion worth of earned media, although the most recent Federal Election Commission documents show his campaign has cost little more than $33 million as of February's end.

In other words, for every dollar his campaign has spent, Trump has received nearly $58 in free press — and that's including all of his campaign's expenses, not just advertising and other paid media.

No other candidate comes anywhere near that return on investment. Clinton, the biggest spender in the race, comes closest. In exchange for $129 million in overall campaign disbursements, she has received an estimated $746 million in earned media. Where Trump gets $58 for each dollar spent, Clinton gets roughly 10 percent of that.

And Sanders? Despite spending almost as much as Clinton, he's struggled to find a foothold in prime time. For $123 million, Sanders has earned $321 million in press attention, or a little more than $2.50 for each dollar his campaign has spent. Kasich, who has spent less than $11 million and won just one state so far, has received approximately $3.50 in free media for each dollar from his campaign.

Sanders supporters have accused the media of largely ignoring their candidate, and these numbers suggest they may have a point. The question for the campaign is whether they can still get their message out through grassroots organizing, social media and other avenues.