While the 1979 campaign was dominated by the image of the "Labour isn't working" dole queue, and the 1997 poll by Tony Blair's five key pledges, many of us would probably struggle to name a roadside billboard we have seen during this campaign.
There is good reason for this. While campaigning in past elections was a relatively simple affair, relying on garish leaflets and posters, today's strategists use methods so subtle we might not even notice them. And it is social media sites such as Facebook, rather than large advertising hoardings, where the battle for our votes takes place these days.
In the run-up to the 2015 General Election a total of £1.3m was spent on targeted Facebook advertising by political parties, about 23 per cent of the total advertising budget.
But if experiences of subsequent polls are anything to go by, that figure will be dwarfed by the amount spent by the time we get to June 8.
Dominic Cummings, campaign director for Vote Leave during the Brexit referendum, claims his group spent 98 per cent of its £6.8m budget on digital advertising, publishing nearly a billion targeted digital adverts, mostly via Facebook.
Across the Atlantic, in just one day in Augusts, Donald Trump’s campaign showed ads to Facebook users that linked to 100,000 different web pages, each micro-targeted at a specific group of voters, according to the campaign’s digital director Brad Parscale.
The Bureau of Investigative Journalism, which has been closely examining the trend in the run-up to next week's election, has identified at least 68 different types of political adverts paid for by the main political parties over the past month.
From the strategists' point of view, social media advertising has two main advantages. Firstly, it is more cost effective than the more traditional methods, targetting large numbers of people for comparatively little outlay. But the other, and perhaps more disturbing feature is that sites such as Facebook are able to harvest key data about potential voters from their profiles, and use it to target material towards an individual.
Will Moy of the independent fact-checking website Full Fact has described the phenomenon as a "dark ads" election, and warns it could have sinister consequences.
"It's possible to target dark ads at millions of people in this country without the rest of us knowing about it,” he says. “Inaccurate information could be spreading with no-one to scrutinise it. Democracy needs to be done in public.”
The huge amount of personal information held on each person's Facebook profile allows political parties to target different ads at different people, depending on their demographics, interests or background.
Facebook can provide data on different users’ ethnicities and occupations and what issues they care about, allowing campaign teams to target specific voters with specific messages.
But the Bureau warns that unlike billboards or newspaper ads which everyone sees, the world of targeted advertising is extremely hard to track.
"For the first time in history it's possible to target dark ads at millions of people in this country without the rest of us knowing about it"
Of the 68 Facebook adverts identified in the Bureau's investigation, the Liberal Democrats appear to have been the most prolific. The party itself took out 34 adverts, with a further 10 coming from Tim Farron's official account.
Labour took out 14 advertisements, and the Conservatives 10.
The Bureau found the Conservative party consistently attacked Jeremy Corbyn by name in each of its 10 ads, with mention of Theresa May as a positive alternative in nine of them.
The Bureau found Labour and the Liberal Democrats preferred to use surveys and petitions as a way of gaining email addresses of potential voters.
The problem for our democracy is that while the traditional billboard, press and postal advertising is subject to strict regulation and scrutiny, much of what appears online is unmonitored, with only Facebook knowing what users are being shown. Privacy and commercial interests mean that information is not publicly available.
Facebook's own business page claims that at the 2015 election the Conservative Party served ads to 80 per cent of the site’s users in the key marginal seats.
"The party’s videos were viewed 3.5 million times, while 86.9 per cent of all ads served had social context — the all-important endorsement by a friend,” it said. “Facebook played a vital part in a highly targeted campaign, helping the Conservatives speak to the right people—over and over again.”
It is a sobering thought that for all the claims of Russian interference in the US presidential election, it may be American billionaire Mark Zuckenberg who is quietly influencing the result of the vote over here.
