ABC News' Shushannah Walshe, Michael Falcone and Jake Tapper and report:

MANCHESTER, N.H. - Enjoying a wave of momentum from his near-win in the Iowa caucuses, Rick Santorum's campaign is raising money faster than ever before. Donors have added $2 million to his campaign's war chest in the last 48 hours alone.

And a Santorum aide tells ABC News that in the space of 10 hours - between midnight Thursday and 10 a.m. - the campaign took in $250,000 of that $2 million total. The quarter-million figure total represents online contributions only.

What's the campaign doing with that fresh infusion of cash?

For starters they are taking out a 1,000-point television ad buy in South Carolina ahead of the state's Jan. 21 primary.

The campaign is calling is a "major buy," and an adviser to the former Pennsylvania senator's presidential bid told ABC News the spot will

play heavily on cable. According to a GOP source who tracks ad spending, the Santorum campaign has only spent $12,000 on the airwaves in South Carolina so far during the election cycle.

The Santorum campaign also plans a heavy mail drop in the state that begins early next week.