The first priority for any inventor is to find customers for his new invention. Early telecommunication entrepreneurs had to use their best business and social connections to get both investors and customers. Today we'd call it 'word-of-mouth marketing' - but in Victorian times they didn't think that way. This was a different age, with different language and expectations.
The idea of using a telephone for anything so frivolous as a chat was quite unthinkable in the 1870s. Besides, early telephones were priced to discourage casual use.
In the end, sweeping changes were needed in society before the telephone could really become universal.
The way radio broadcasting was 'sold' was rather different. Nobody actually needed to listen to the radio - but people soon found they wanted to, as the quality of programmes improved. Once again, wireless sold itself - this time on the strength of its content.
Ways in which the people running the networks talked to the people using them changed radically during the late 19th century. The transfer of the telegraph and the telephone systems to state control (between the years 1870 and 1912) led to a change in the whole tone and language of communications aimed at users and subscribers. In fact, most of the time, it wasn't really marketing at all.
Many felt the private companies had made an unimpressive job of providing high quality and good value phone services and most Britons were not sorry to see the service taken over by the General Post Office (GPO).
With the change came new bodies charged with talking to telephone users - or 'subscribers' as they were called then.
The new network made it ever easier for people to call long distance. But phone users needed to be told the new capability was there.
After the First World War, telecommunication providers began to move to the modern era - one in which they were selling devices like the telephone and services like telegrams direct to the customer. For the Post Office, now in charge of almost all telecommunications in the UK, the first challenge was what to tell people about the telephone services it was providing. The second challenge was how much it should be persuading or helping the mass of the British people to get connected.
There was a good reason for that. The truth was there weren't enough lines to go around and more people wanted a telephone than the GPO could supply. It was only once the supply problems had finally been addressed in the sixties and seventies that the telephone network could be sold aggressively again.
A particular hotbed of creative energy was the GPO Film Unit, one of the most remarkable creative institutions that Britain ever produced. The unit incorporated the contributions of acknowledged film-making and literary giants.
Sometimes, the communications campaign has been driven by needs other than increasing usage and business. In war and in times of national crisis, there are other messages that need to be put across... where the needs of security or national welfare have to come first. This was what happened during the Second World War. And afterwards the change in British society meant that post-war communications campaigns were very different from what came before.
The demands of military security and national priorities meant they had to be urged to use the service less - and with more care.
It looked as though the post-war era would be a brave new age of scientific progress and creature comforts. But the reality - austerity, rationing and economic crisis - proved a little different from the vision.
During the 1960s and 1970s the Post Office had to face more and more commercial realities - the need to keep the network growing, the need to increase the user base and, more importantly, the need to keep increasing traffic. The telephone service became increasingly seen as a business rather than a public service - and more and more driven by public demand, rather than Civil Service whim.
It also witnessed communications from the GPO, which reflected some of the youthful optimism of the decade.
This was reflected in the telecommunication business, hampered by Treasury spending limits on new investment at a time when demand was soaring.
In 1980 Post Office Telecommunications was a government-owned 'public corporation'. By the 1990s BT was a mature global commercial company - one of the biggest of its kind in the world.
The 1980s saw everything change about telecommunications in Britain. The ownership changed - taken out of the Government's hands and into a privately owned company. The industry changed - becoming liberalised and competitive. The technology changed - from analogue to digital. The design of devices changed - becoming smaller and smarter. And the whole mindset changed - seeing telephone users no longer as captive 'subscribers' but as customers with a choice.
Yet they did possess brand value - people associated telephones with Post Office vans and call boxes along with an expectation of expertise built up over almost 100 years.
When the Post Office gave way to British Telecom, the new company had to redefine those values and expectations.
At the same time, a small team within BT was working on a radical change of image - one built around a completely new idea of the company BT was aiming to become.
