Advertising is huge business. Companies are constantly looking for new ways to reach consumers and some are turning to new technology to make their brands stand out from the rest.
Last year, $6.3bn (£3.3bn) was spent on posters, neon lights and other out-of-home advertising in the US alone.
Could ubiquitous adverts be the future of advertising?
Advertisers will jump at the chance of looking cool, and getting more bang for their buck, wherever their ads may be.
If you believe some agencies anything that is currently paper and paste is going to become video.
This not only gives the benefit of looking snazzier, but you can change the ad to anything you want, anytime you want. All of a sudden ad campaigns do not last a week, they last 10 seconds.
For the first time, out-of-home advertisers can fine-tune their messages to the audience in that part of the day
In the underground station of the future video rules. Messages will follow you up the escalators on LCD screens, they will even be projected onto the wall as you wait for your train.
James Davies, of out-of-home advertisers Posterscope, says: "We can run adverts that are only on display at a particular time of day. We can change the copy and creative on our adverts at the click of a switch."
That so-called '"dayparting" is a real money maker for media owners.
For the first time, out-of-home advertisers can fine-tune their messages to the audience in that part of the day.
A fast food chain can advertise either breakfast, lunch, or dinner. A newspaper may only want to advertise in the morning, a bar only in the evening.
Ad agencies can sell their precious real-estate to more than one advertiser at the same time.
Some ad agencies are trying to be even more specific in who they target.
Using a camera and facial recognition software, there are prototypes that can not only detect a face looking straight at it, but also guess whether it is male or female, and change the ad accordingly.
Possibly more important than grabbing our attention is keeping it, and that is where advertisers have started to use the dreaded "I" word - interactivity.
'Interacting' with adverts can make the products more memorable
Interactive ads have started to appear at bus shelters, where people have time to wait around and play with them.
James Davies says: "We do know that if consumers interact and actually get involved with advertising campaigns they are much more likely to remember what they've come across.
"A lot of that is due to the psychology of advertising, and the fact that by getting people interacting it actually sparks an emotional response in the brain as opposed to a purely intellectual response."
Of even more value than simple interaction, are ads with so-called "added value", the ads that let you take a little piece of them away with you.
Last summer, Coldplay launched their new album by letting fans download songs to their phones from posters with special Bluetooth transmitters.
Currently emerging prototypes even offer applications allowing users to download a special browser which can then be used to download more themed content, such as games, from the poster.
All this only works assuming that we are happy to accept Bluetooth connections from adverts, but are the advertisers asking too much?
Technology journalist Tim Phillips says: "All the sound advice that people are getting about using Bluetooth is that you don't leave your connection open, you don't let people you don't know just download stuff onto your phone from locations when you don't even quite know where it's coming from.
"This flies in the face of all good security common sense."
We are seeing technology starting to be used in advertising in a way the sci-fi films have been suggesting for years.
Images that float in the air, ads that change to suit our sex, and all our spending habits recorded, linked and used to provide individually targeted ads, specific to each person.
James Davies says: "Everybody cites Minority Report and Blade Runner as the future of out-of-home-advertising, and that's a big exaggeration.
"We're not going to see screens on every single street corner over the next few years, mainly because of costs, to be honest with you, these are very expensive forms of technology.
"And from a planning permission perspective, you can't start serving up ads on the side of the road because it's dangerous.
"In terms of one-to-one advertising, where the screen knows who you are when you are standing in front of it, from a technology point of view it is possible; are consumers ready for that? I'm not so sure.
"Are advertisers ready for that? Probably not either. So we are quite sensible in terms of our approach to the future."
Tim Phillips says: "In the West we maybe see, at a conservative estimate, 500 advertising messages every day. We see as many advertising messages in a year as our parents saw in their entire lives.
"The problem is that we have learnt to screen them out, so interactive advertising, where we make an effort to actually receive the information, is great because at least it means we are interested. It has to be the future of advertising.
"The problem for advertising people is that we are not interested in nearly as much as they'd like us to be."
It is all very well having the technology to produce 21st Century ads, but it has to work, and by that we mean that it has to catch our attention and get its message across.