The recent referendum for Scottish independence was a poster battleground on outdoor sites across the nation.
The vote for independence had a wonderful powerful strong slogan, "Vote Yes", while the slogan for staying in the union, "Better Together", was a bit mumsy.
However, the 'Better Together' campaign used fear and urged Scots not to risk "pound, pay and pensions", while the vote 'Yes' campaign used posters that featured an image of a baby hand in an adult hand, and the slogan, 'Scotland's Future in Scotland's Hands'.
Other posters reminded the population of the plethora of Scottish inventors and the promise of living in one of the world's wealthiest countries.
It was a fascinating campaign because neither party failed to decisively prove that Scotland would be better or worse off as an independent country. As a result a number of people who sat on the fence decided to stay with the status quo.
I wonder if things would have been different had the 'Better Together' campaign not used fear as the prime motivator in their advertising messaging?
The UKIP European election victory earlier this year clearly demonstrated the power of using fear in billboard advertising campaigns.
The campaign was funded by businessman Paul Sykes. It propelled UKIP to victory in the European elections and in the process broke the hundred year stranglehold that the Tories and Labour have held over national elections.
The poster campaign focussed on an anti-immigration platform and ran several edgy creative executions. One poster featured a burning Union Jack flag while another portrayed a British construction worker driven to homelessness as a result of "unlimited cheap labour."
The latter campaign sat uncomfortably with many and actually caused ex-KLF front man Bill Drummond to modify (through graffiti) one of our posters in Birmingham with his grey paint because it offended him morally and aesthetically.
The story that ran in the Birmingham Post actually had 11,530 shares, clearly demonstrating the public interest in the story.
For the 2010 election campaign we saw an increase in the number of election posters defaced.
The David Cameron poster that featured the strapline "We can't go on like this" was defaced. An Elvis quiff was added to Mr Cameron, as was the line "with suspicious minds", which appeared in the Daily Mail and led to a number of copycat amendments to posters across the country.
Facebook pages like the Defaced and Graffitied Tory Poster Community were set up, which allowed this work to be shared on social media.
Twitter was still in its infancy in 2010 with only 7% of its current users (statista.com). Therefore, we are likely to see a significant increase in election posters that are shared online, particularly if they lend themselves to Photoshop or street art.
Billboard advertising will be a vital battleground in the 2015 election campaign. It will be interesting to see what messages the various political parties use and the choice of negative or positive tone.
The UKIP campaign was successful because they managed to get the creative right. It matched the mood of enough discontent voters and got them to the polling booths. However, getting the creative right is extremely difficult and fear as core message can also be deployed badly.
The Conservative posters from 1997 featuring Tony Blair, and the devil eyes campaign with the slogan 'New Labour New Danger' failed to connect with the public probably because young voters had no experience of a Labour government.
Compare this with the 1979 'Labour Isn't Working', which featured an endless queue of people standing outside an unemployment office. The election poster is generally seen as one of the best and was denounced in parliament, which only added to its fame.
Dennis Healey proclaimed that the Conservatives were dishonest, reaching a new low by "selling politics like soap-powder".
The formula for successful political campaigns was thus created: put up some hard hitting posters that emotionally connect with the public and then get the press and TV (and now social media) to amplify the message.
Sounds easy but getting the creative right will remain the big challenge for the political parties. The prize is big though. The winner on the billboard may just go on to win the election.
Naren Patel is Chief Executive of Primesight
First published in Media Week