Where coverage is low and sanitation technologies are unfamiliar, primary demand for sanitation must be created from ‘scratch’. This is particularly so in households that have never before allocated money, time or effort to buying, building, and maintaining home sanitation systems. Much can be learned from the commercial sector which has brought new product categories to the market and generated such demand for them that they are now considered household necessities. Examples include the proliferation of home computers and mobile phones, where demand did not exist just 10-15 years ago; or the spread of TVs, CD players and, longer ago, radios. The commercial experience has clear and important lessons for sanitation promotion. One of the most significant is that it requires a much greater investment upfront in promotion and consumer education. It also requires a longer timeframe to launch a new product category and achieve successful sales growth, than when launching new product brands or “flavours” into an already well established product market, e.g., a mint and sage sausage into the sausage market. Latrine building and use is a new product category for which consumer product knowledge must be created from scratch in rural areas where sanitation coverage is low.

An analysis of a wide range of new consumer durables introduced in the US showed that before WWII it took about 18 years for newly introduced product categories in the market to reach ‘takeoff’ (an elbow-shaped discontinuity in sales growth representing a sudden dramatic increase in early sales) (Golder and Tellis 1997). Since World War II this has gradually reduced and now takes about 6 years. These shorter takeoff times have been due to much faster technology-based communication. This in turn promotes the rapid spread of information and awareness about new products. Increased rates of travel further enhance the rate of information dissemination and the growth of large national and multinational retail networks can make new products widely available in a short space of time. In many developing countries among the un-served segments of society, communication, distribution networks and capacity to travel are at Northern pre-WWII levels at best. The uptake of new products, services and behaviour will therefore be slow without interventions specifically designed to stimulate demand and enhance uptake.

A similar phenomenon of new product uptake in sanitation can be seen in the following examples. The sales growth of low cost dome slabs in Maputo, Mozambique under the National Sanitation Program (Fig 1); the spontaneous uptake of latrines in rural Benin well before any sanitation programme ever operated (Fig 2), and the steady acquisition of household toilets in Bangladesh since the 1980’s (Fig 3). Uptake curves like the ones in Figs 2 and 3 show how adoption expands over time as information spreads slowly from adopters to non-adopters (and through other channels if they exist) all of them by face to face contact in a rural context such as Benin. It is important to recognise that improved sanitation is a technological and cultural innovation in defecation practices in these communities that must be understood, appreciated, valued and adopted for the first time. Diffusion of innovations, or the study of how innovations spread, has much to teach us in sanitation (Rogers 1984; Gatignon and Robertson 1985).

Fig. 1. Sales of Latrine Slabs under the National Sanitation Program in Maputo, Mozambique (Table A-1, # 10)

Fig. 2. Latrine Uptake by Rural Households in Zou Department, Benin (Jenkins 2004).

Fig. 3. Latrine acquisition curve for Bangladesh where a national social mobilization and marketing approach was adopted in the early 1990s (Cairncross 2004)

As with any innovation, households will not adopt in a uniform manner. The categories of innovator, early adopter, late adopter and laggard are as relevant to latrine building in developing countries, as they are to the adoption of compact disc players or mobile phones in developed countries. The decision of a householder to build a latrine is what Rogers (1984) describes as an ‘optional innovative decision’ where the choice to adopt or reject an innovation is made by an individual household independent of the decisions of other members of the community. Peer-pressure and social norms no doubt play a part in this decision-making process, but the decision itself is a private one.

An in-depth study of demand for latrines in rural Benin looked at the diffusion of household latrines. This was achieved by mapping latrine adoption rates over space and time, to investigate how and why people decide to change from open defecation to installing a pit latrine at home, and why others do not (Jenkins 1999, 2004). Large differences in adoption existed across villages, and across households within them, with much greater demand clustered in villages located around urban centres and along roads. Latrines were clearly seen to be spreading outwards from urban centres and along road networks and a significant spatial contagious aspect to latrine adoption was observed in the regional data.