If previous contests are anything to go by, the answer to this might be quite a lot.
"They qualify for a very privileged circle, with money and influence," said Buchanan, who currently lectures about the criteria for a successful presidential campaign at the University of Texas in Austin.
Conservative activist Gary Bauer, a domestic policy adviser in the Reagan White House, pulled out of the 2000 presidential election after a poor showing in the primaries. Since then, Bauer founded the nonprofit, anti-abortion group American Values, has occasionally co-hosted a radio talk show, and told ABC News that when he is giving a speech anywhere other than a church or synagogue audience, "I normally expect between $5,000 and $7,000 for my public appearances."
It's not only the fringe players who benefit from the experience of running a presidential campaign. Even a loss can raise a politician's public profile -- to their benefit.
Howard Dean became the governor of Vermont after his predecessor Richard Snelling died in office, but after 12 years in the gubernatorial chair he launched a presidential bid for the 2004 election. Though he lost out to Sen. John Kerry for the Democrat nomination, successful Internet fundraising during his campaign helped land him the job of chairman of the Democrat National Committee.
"Howard Dean did sufficiently well in his presidential run to become a major player in Democratic politics, which he would not otherwise have been as the ex-governor of a small state," said Professor Mayer.
Former Sen. Bill Bradley, D-N.J., was defeated by Vice President Al Gore in the 2000 primaries, but a previous high-profile role with investment bank JP Morgan was followed in 2001 by his appointment as adviser to the premier consulting firm McKinsey & Company.
Bradley was also given a managing director role at the well-connected New York bank, Allen & Company, and given a seat on the Starbucks corporate board.
Former Sen. Gary Hart failed to make the Democrat ticket in both the 1984 and 1988 campaigns. Since then Hart has assumed the role of a national security expert, co-chairing a Clinton administration panel aimed at safeguarding American interests in the post-Cold War era and studying for his doctorate on Thomas Jefferson's American ideals at Oxford University.
Alan Keyes was considered a serious long shot when he pursued the Republican nomination in both 1996 and 2000. Since then the Harvard doctorate has kept himself busy, hosting a 2002 MSNBC talk show, writing books and reportedly earning between $10,000 and $20,000 for public speaking appearances.
So there is some hope, even for the long shots, according to Mayer's research. "Normally the nomination is won by the early front-runner, but hope springs eternal with these people," he concluded.