This study "Spatial patterns in the spread of SMS in different countries" claims that SMS is more frequently used in the larger cities than in the rest of a country. The authors then explains how innovation spreads from major cities to more provincial areas.
However, does this fact suffice to conclude that this innovative communications service primarily concerns urban dwellers? How can we conceive SMS diffusion throughout a country's territory? Geographic research has shown that the spatial diffusion of a technical innovation like the SMS most often starts in urban systems in major cities, and then spreads to provincial centres and finally to peripheral regions. This is called hierarchical diffusion. While diffusing top-down, the innovation also radiates from the diffusion centres to surrounding areas. Here we have a so-called contagion effect. When comparing SMS penetration rates among mobile telephone users simultaneously by country and size of city, we see that these two effects co-exist.
In countries with low SMS penetration rates, such as the UK, Spain and Denmark, there is little urban-rural difference. Diffusion has not yet really started, so the penetration rate is low everywhere.
By contrast, in the Czech Republic, a country of recent, rapid and strong mobile diffusion, it is mainly the inhabitants of the Prague region who use SMS. In Norway and France, two other countries with a strong population concentration in the capital, the large number of inhabitants facilitates the imitation of modes of communication and thus the diffusion of SMS from the centre. In these three countries we observe a process of "hierarchical diffusion".
Finally, in the Netherlands, a country of high population density, a relatively egalitarian culture and a high penetration rate of the mobile telephone and SMS, the tendency is the opposite of that observed in the Czech Republic. SMS penetration rates in urban agglomerations surrounding the large cities are as high as those in the cities themselves. By contrast, in medium-sized towns like Groningen, relatively far-removed from the main agglomerations, the SMS is used less often. This is an example of diffusion which also includes a contagion effect due to the geographical and cultural proximity of urban centres in the Netherlands.
