Andrew Sullivan brought up the discussion about lawn signs.
They're both deceptive and helpful, if that's even possible.
A good political sign can help with the branding of a candidate, and a large number of signs can create a bandwagon-style buzz for a candidate, at least at a state and local level where name recognition doesn't quite rival congressional and national candidates. Voters will sometimes latch onto a candidate simply because he or she appears to be popular with their neighbors. That can drive votes.
But at that national level, it becomes more of a campaign volunteer pissing match than anything else, with workers trying to one-up the opposition by planting more of their flags in strategic locations. Voters, too, will often plant a flag for their candidate as a way of advertising themselves more than the candidate. Look who I support, bitches! But, unlike local signage, name recognition and branding is already established, especially by presidential candidates. Therefore, signs are window dressing and a reminder to voters that Candidate X is still running.
And that's where the signs become deceptive and annoying. Just because Terry McAuliffe had a gazillion signs planted in Virginia didn't mean he was any closer to winning last year. In other words, signs don't equal votes.