He knows he will never be the GOP nominee, he knew that well before before he got into the race.
Ron Paul knew that there was a lot of money in being anti-war in the 2008 election cycle.
He also knew that there are plenty of fringe groups with donor lists that are able to bring in donations year in and year out - he was a former Libertarian presidential candidate, for goodness' sake.
So he put together a campaign calculated to appeal to the maximum number of fringe donors - a campaign that has found favor among radical libertarians, John Birchers, 9/11 Truthers, loony tax protestors, Bev Harrisers, the Liberty Lobby, Stormfronters, Henry Georgites, goldbugs, etc.
He is the great new hope of every random whackjob in the USA - and he will take all their donations, make as many ambiguous comments as he needs to in order to hint to them that he supports their various agendas, and then count their money.
He will spend next to none of it, depending on all the saps he attracts to spend their own cash on rallies, meetings, flyers, t-shirts, etc.
Then, when the charade has gone as far as it can go (the GOP Convention), he will do the math and see how much more he can raise by running 3rd party.
If the numbers don't work, he will bow out with millions of donations still in the kitty.
And he will have accomplished the goal he was working toward in the first place: raising enough cash to finance his next three or four Congressional campaigns.
One year of stumping as an anti-war candidate in a hot election cycle for anti-war loonies will save him years of future work raising money to keep his Congressional seat.
Ron Paul is laughing all the way to the bank while the poor clowns who actually believe he could ever have a shot at the nomination do all the work.