Des Moines, Iowa (CNN) -- Mitt Romney won the Iowa caucuses by eight votes. However, Rick Santorum came out of nowhere in the course of two weeks to grab a narrow second-place finish and become the latest Republican to seize the anti-Romney mantle.
So what did we learn from Tuesday's historic vote?
Mojo trumps money
Make no mistake: Money mattered in Iowa.
Newt Gingrich was torpedoed by a barrage of negative ads and mailers from Ron Paul's campaign and "super PACs" backing Mitt Romney.
But money can't buy you Iowa.
After he stumbled badly in several debates, Rick Perry tried to right the ship by dumping more than $4 million into a wave of television ads in Iowa. Some were positive, some were negative. But all that television spending bought him only 10% of the caucus vote (about 12,600 votes).
That's almost $350 per vote.
Rick Santorum, meanwhile, spent about $30,000 on television ads and won about 30,000 votes.
Do the math. For Santorum, momentum and lucky timing were more valuable than paid media.
Romney's ceiling isn't getting any higher
The importance of Romney's win in Iowa -- the closest caucus vote in history -- should not be understated.
His Iowa team, led by veteran operative David Kochel, ran a sneaky and near-flawless campaign. With his first-place finish, Romney can put to rest the weak Iowa showing of 2008.
However, the Romney camp should still be anxious about his winning number: 25%. It's a vexing figure. In poll after poll this year, Romney has steadily registered at around... 25%. Translation: A full three-quarters of Republicans are searching for someone -- anyone! -- other than Romney.
Despite his chilly relationship with conservatives, he has survived, as he did in Iowa, because those anti-Romney votes have been divided up among several candidates.
It seemed on Tuesday night that Perry and Bachmann might soon drop out of the race. That's bad news for Romney.
As the size of the field shrinks, so does Romney's opportunity to skate through primaries with a plurality here and a plurality there.
If Santorum or Gingrich can raise money, get organized and stay disciplined, one of them has an opportunity to rally the right and become the conservative challenger to Romney.
Evangelicals still matter
Evangelicals made up about 60% of the caucus electorate in 2008, but heading into this year's caucuses, polls suggested that the number might be lower.
In the closely watched Des Moines Register poll released on Saturday before the vote, just 34% of likely caucus-goers described themselves as "born again" or "fundamentalist Christian."
But according to entrance polls on Tuesday, 57% of those who caucused called themselves evangelical or "born again."
Christian voters showed up but did not rally behind a single candidate like they did in 2008, when Huckabee captured their imagination.
But Santorum, a Catholic and staunch abortion opponent who courted pastors and home-school activists during his campaign, outperformed his opponents and won a third of the evangelical vote.
That's a big slice of a crucial Iowa voting bloc that surely helped Santorum to his second-place finish on Tuesday.
The zenith of Michele Bachmann's boom-and-bust campaign was her victory at the Ames Straw Poll last August, when she captured 4,823 votes and, in the process, dispatched her main Iowa foe at the time, Tim Pawlenty.
In the caucuses on Tuesday night, almost five months after Ames, her numbers were dismal. Only about 6,000 Iowans cast ballots for Bachmann.
The results of the straw poll, a Republican political carnival beloved by party activists and the media, are not meant to be predictive.
Romney won the beauty pageant in 2007, for instance, but came up short against Mike Huckabee in the 2008 caucuses. He took a pass on Ames this year, but won the caucuses on Tuesday.
The straw poll was designed as a test of each campaign's organizational strength in Iowa, and it has been a somewhat reliable indicator of which candidates were catching on with the Republican base here.
But with Bachmann's epic collapse after Ames rendering last summer's straw poll next to useless, there will almost certainly be questions about whether the next contest merits the attention it usually gets.
And maybe next time, someone like Pawlenty might think twice before dropping out after a poor showing.
The Iowa way or the highway
When Pawlenty quit the race in August, it seemed to suggest that the traditional path to victory in Iowa -- hiring veteran operatives, lining up campaign chairs in every county, and holding small town hall meetings -- was a non-starter.
Pawlenty did all of those things but failed to catch on. Instead, presidential debates and cable chatter closely watched by Republican activists in Iowa seemed to drive poll numbers and define the shape of the race.
But when crunch time arrived, the three candidates who did things the Iowa way won a coveted top-three finish in the caucuses.
Winning a caucus requires organization, and to varying degrees Romney, Santorum and Paul were able to turn out a reliable network of supporters who showed up for two or three hours on a Tuesday night to support their guy.
All three candidates had been planting seeds in Iowa for years.
Romney and Paul had both run in the state four years prior and quietly kept in touch with their backers until it came time to run again.
Santorum did not have the resources to build a formidable ground game, but his hard work -- he did almost 380 campaign events in the state beginning in 2009 -- laid critical groundwork that helped him capitalize on his late and perfectly-timed bump in the polls.