The two candidates also agreed that "neither they nor anyone acting on their behalf shall coordinate with any third party on any paid advertising for the duration of the 2012 cycle." When it comes to most outside groups, this agreement is largely immaterial, as the law already prevents any coordination. There are examples of coordinated expenditures between campaigns and other entities (for example, in Oregon's 1st District special election, the National Republican Congressional Committee and the campaign of Republican Rob Cornilles recently made a coordinated ad buy), but the most significant buys tend to come from outside groups that cannot coordinate. Finally, the candidates agreed to something broader, a bit more vague, and less enforceable: to "continue to work together to limit the influence of third party advertisements and to close any loopholes (including coverage of sham ads) that arise in this agreement during the course of the campaign." What impact it will have: Possibly none, due to the most important factor at issue -- outside groups can't coordinate with campaigns. So the candidates cannot stop groups from advertising for them or against their opponents. Secondly, as the Boston Globe notes, broadcasters, as both campaigns acknowledged, are unlikely to turn down the advertisements from outside groups, regardless of any agreement. They make millions in campaign TV ad buys. All that said, there were some tangible effects on Monday. The League of Conservation Voters, which the Globe reports has spent over $2 million dollars attacking Brown with ads, issued a statement indicating it would comply with the agreement. "While we cannot take directions from any candidate on our independent activities, we are inclined to respect the People's Pledge agreed to by Elizabeth Warren and Scott Brown and we hope that Scott Brown will honor his end of the deal when Crossroads and the Koch Brothers inevitably break it," said League of Conservation Voters Senior Vice President of Campaigns Navin Nayak. American Crossroads, the powerful GOP aligned outside group that has already hit Warren on TV, said the agreement had loopholes that could be exploited by Warren, and did not commit to any specific action. "Because the agreement allows union phone banks, direct mail, and get-out-the-vote drives -- all union core specialties -- Warren's latest agreement has loopholes the Teamsters could drive a truck through, the longshoremen could steer a ship through, the machinists could fly a plane through, and government unions could drive forklifts of paperwork through," said American Crossroads President and CEO Steven Law. Why nasty ads will air regardless: Brown has over $12 million in the bank and Warren raised an eye-popping $5.7 million during the 4th quarter. The money continues to flow into the campaign coffers, regardless of the influence of outside groups, ensuring a war of words over the airwaves will ensue either way.