And fulfilment must always be brought into the equation: goods that are heavy or bulky will be harder and more expensive to sell online than light, easily transportable ones.Then there is the question of what kinds of goods and services sell well electronically.
Andrew Dillon, the agency's chief executive, accepts that "the NICE model is not transportable in precise form" but he still insists that "one can dissect and apply what is relevant to other countries".In America, the drugs and devices lobbies are violently opposed to a NICE-style agency that could issue mandatory rulings.
Richard Elliott of Band-X, a leading bandwidth exchange, notes that bandwidth is quickly and easily transportable, without losing its value.
But when Nichodemus Gebe, head of biomedical engineering at Ghana's Ministry of Health, started looking for specialist gear he was unable to find any easily transportable treatment units able to contain the virus.
Some cities, notably New York, have long had more ambitious vendors egg cakes in Chinatown, arepas in Queens but these are not mobile kitchens so much as transportable ones: they set up on a street corner and stay.One advantage of trucks is that chefs can go to where the diners are.
It is a programmer's dream: computers running the world's online marketplaces on behalf of their human masters.Just as computers need to convert the world's complexity into digital bits before they can make sense of it, these futuristic digital markets need a correspondingly electronic currency: something as liquid and simple as cash, yet as international and transportable as a credit-card number.
That makes transportation costs cheaper for Asian factories.Garments are a natural first step in the spread of production out of China: they are low-skill, low-cost and highly transportable.
The most transportable form of energy, though, is electricity, so systems that convert waste heat into electricity are also desirable.
Meanwhile, the benefits to a college education accrue over the whole of an individual's life, while a home's benefits are enjoyed only as long as the home is occupied.Moreover, the benefits to a college education are transportable.
But specialist fuels and constrained cooking times can restrict their appeal.As well as being efficient, stoves must also meet the conflicting objectives of being transportable and being rugged enough to withstand the rigours of daily cooking.
Since coins of that period are universally recognized as works of art, and since they were among the most affordable and transportable objects of the art world, it is not surprising that they would have been collected even then.
