Fundraising receives a great deal of attention in politics. But looking at how campaigns and outside groups decide to spend money can be just as revealing.

If it seems as if various organizations are bringing in and shelling out eye-popping heaps of cash in the presidential election, it's because that's exactly what's happening. As The Washington Post's 2012 Presidential Campaign Finance Explorer shows, President Obama and his allies (including the national Democratic party, a joint fundraising committee, and super PACs) have raised $775 million and spent $606 million. Mitt Romney and his allies have raised even more ($784 million) and spent $534 million.

So where is the money going? Much of it has gone toward advertising, including television and radio spots. TV advertising remains one of the most effective means of mass communication with voters. It's also very expensive. Running a single ad can cost millions of dollars in the biggest media markets.

Both Republicans and Democrats have dedicated more to advertising than any other type of expense. Obama and his allies have spent roughly $121 million more on advertising than the GOP side, about $266 million to Republicans' $145 million, as the chart above shows.

Interestingly, Romney and his allies have dedicated about $29 million more to mail than Obama's side, dishing out nearly $100 million. Direct mail is a much more targeted medium that leaves room for tailoring messages to specific parts of the electorate.

When it comes to payroll and administrative costs, Obama and his allies are outspending the Romney side, suggesting that in terms of staffing and other operational expenses, Republicans may be running a leaner operation. That said, the GOP side has been spending more on consultants.

Ann Marie Habershaw, the Obama campaign's chief operating officer, represents the payroll top expenditure on the Democratic side, while the GOP side's top payroll expense has been Republican National Committee Chairman Reince Priebus.

The data also show that it's true you have to spend money to make money in politics. Both sides have spent about $70 million on fundraising.

One more notable observation: Obama's side is outspending Romney and his allies more than 2-1 on polling.

Check out the complete Campaign Finance Explorer here, where you’ll also find a complete list of the groups that were included in the spending tally, as well as more details about specific expenditures.