A nutty idea or a business solution of the future?

That is a question that often comes to mind when I encounter applications for the Business Innovation Facility (BIF) or Innovations Against Poverty. Every one seems a great idea - but is it an idea that will take off? It's not just a question of whether the technology will work, but will people in their thousands and millions really change how they cook, farm, interact, or shop? Or will the project bumble along as just another nice idea, supported by the conviction of its enthusiasts and early adopters?

If you work in inclusive business you probably have one or many projects that inspire and convince you. Conviction may flag at times. But mine was reinforced yesterday, thanks to a delightful half hour of lunchtime radio. Stephen Fry (journalist, entertainer, technology-lover) has presenting a series each day on the history of the mobile phone, on BBC Radio 4.

That the pace of technological change exceeds our expectations is well-known. Not many realised how the initial 1.5kg phone would end up fitting into a pocket. But what struck me was the degree of scepticism that met Motorola's initial idea in 1973 and the early roll-outs of the eighties. 'Why would you want a phone that went with a person not a place?' the sceptics asked. 'Oh no', they said in Britain, 'people here wouldn't want to walk down the street having a phone conversation.' How things change.

So if you would like a cheerful reminder of how a whacky idea can end up relied on by millions - including users across Africa and Asia, I recommend the series. But be quick. The BBC website has them as podcasts (which you can download to an MP3) until next Friday. They are also on I-player, but I think that cannot be accessed (easily) from outside the UK. Try the podcasts here or search the BBC website.

So which projects in the portfolio of BIF or IAP will end up as future solutions for the masses? Reaching impact at scale, is after all, the logic for investing donor money into inclusive business. To be frank, I have no idea. Of course we try to assess scalability, as well as impact, commercial robustness and degree of innovation. But an early lesson is that what appears in an application form is remarkably different to what is captured (post selection) at the baseline. Whether the aspiration of an application or the data of a baseline is a better guide to future trajectory remains to be seen.

In truth, probably neither - on the page - are good reflections. It's when we meet the entrepreneurs and get a taste of how they combine experience of business with a passion for the future, that we get a sense of what may happen. When I read about low income farmers in Mozambique paying for farm extension, and low-income households in Zambia paying for private health care, the sceptic in me gets the first reaction. But last week we workshopped the baseline with Healthstore Foundation, who seek to set up nurse-led clinics in Zambia with BIF support. They, just like IDE who are setting up extension services in Mozambique with IAP support, are drawing on a franchise model already developed elsewhere. The simplicity is almost stunning: the franchise model keeps quality high, costs low, and puts the local entrepreneur (the nurse running the clinic or the agent providing extension) in the driving seat, driving scale.

We don't know which projects will reach scale though we are getting a better idea of the many constraints to scale (more on this another time). For shorthand, we ask which will be 'the next Mpesa' - the Kenyan mobile payment service that met initial scepticism, was taken forward inside Vodafone with support from a DFID Challenge Fund, and now is used by millions. But Mpesa shorthand can be a bit misleading. It can suggest we are trying to pick winners. We hope our clients win, but as KPMG have said about the African Enteprise Challenge Fund, the donor aim is more to 'start races' rather than to 'pick winners' as a traditional equity investor does. So what happens in the wider market, to the second-movers, and to the path of innovation matters more. Motorola is just part of the mobile revolution after all.

Meanwhile, thanks to Stephen Fry, I am still wondering which of the projects supported - or even those that were rejected - will be the topic of BBC series in decades to come.