It’s nothing new for celebrities to do a few laps around the press circuit for their favorite candidate. Frank Sinatra sang in support of President Kennedy and Mary Tyler Moore preached about President Carter’s stance on women’s issues. This cycle has offered much of the same, though the medium has changed, with stars swapping prime time for YouTube and prepared comments for tweets.

But do star endorsements garner any real public or financial backing for a candidate? The celebrity see-saw of support is certainly in President Obama’s camp this year, but it will be hard to prove that A-listers promoting his campaign create a more positive perception for him, much less if they can spur greater voter turnout.

“The major issue in this election will be if the endorsement is going to affect fundraising,” says Craig Garthwaite, an assistant professor at Kellogg School of Management who co-wrote a research paper published four years ago that estimated Oprah Winfrey’s primary election support for Obama was responsible for more than 1 million votes in his favor in 2008. Based on Winfrey’s popularity, exposure, and platform, Garthwaite concluded that she not only earned the candidate some positive sentiment, but also incited greater turnout. Not even Winfrey has that sort of direct impact on voters this year.

Celebrity fundraising—in the form of personal donations, event hosting, and even bundling hundreds of thousands of dollars from a cadre of other well-heeled constituents—is a significant aspect of this year’s campaign. Jay-Z and Beyoncé fêted Obama at the 40/40 club, and Gwen Stefani brought in more than $500,000 for him, plus Mariah Carey crooned for him and George Clooney played host to an event that raised $15 million. Romney has the big money men and women, but Obama has Hollywood.

The Daily Beast analyzed the worth of all this celebrity support to find out the relative value of each star’s endorsement as measured by press and media mentions. Publicity can be bought in the form of advertisements, or it can be earned in the form of column inches and unsponsored blog posts. Celebrities help attract the latter; there’s seemingly little modern American media loves to cover more than celebrities.

To rank the most valuable celebrity endorsements in terms of publicity garnered, The Daily Beast looked at nearly 100 celebrities who have come out in support of Obama or Romney. We ranked the celebrities based on exposure with the candidate in the last two years across five coverage areas: major newspapers, television news transcripts, Twitter, online news sources, and Google hits. We also considered total money personally contributed to the campaign, candidate-aligned PAC, or national party in the last two years, and money raised in support of the candidate via an event. Contribution figures are according public records maintained by the Federal Election Commission and the Center for Responsive Politics. Funds raised for campaign are according to press reports on events the star hosted or performed for. The celebrities were ranked in each of the seven categories. The ranks were then averaged to come up with a final ranking.

Interestingly, monetary donations do not equal press coverage. Obama’s biggest celebrity donor, DreamWorks CEO Jeffrey Katzenberg, failed to rank among the top 20 in terms of publicity, despite filling Obama’s coffers with $3 million of his own money. Meanwhile, Lady Gaga—who has yet to show up in any donor database but has tweeted her support for the president and appeared at fundraisers—garnered top spots in mainstream press coverage and social media exposure. And, showing the divergence of mainstream news coverage and the online and social media spheres, a celebrity like Clooney was the second most talked-about celebrity in relation to Obama on television and in newspapers, but close to the bottom in terms of Twitter exposure and online chatter. Predictably, only one of Romney’s celebrity supporters managed to crack the list of the 20 most valuable endorsers.