Huge networks like Facebook and LinkedIn have a huge gravitational force in the world of social media — the size of their audiences make them important platforms for advertising and those who want information (for better or worse) to reach as many people as possible. But alongside their growth, we’re seeing a lasting role for platforms and networks focused on more narrow special interests, and today one of them — focused on farmers, of all communities — is picking up a round of funding to propel its growth.

WeFarm, a marketplace and networking site for small-holder farmers (that is, farms not controlled by large agribusinesses), has raised $13 million in a Series A round of funding, with plans to use the money to continue adding more users — farmers — and more services geared to their needs.

The round, which brings the total raised by the company to a modest $20 million, is being led by True Ventures, with AgFunder, June Fund; previous investors LocalGlobe, ADV and Norrsken Foundation; and others also participating.

WeFarm today has around 1.9 million registered users, and its early moves into providing a marketplace — helping to put farmers in touch with local suppliers of goods and gear such as seed and fertilizers — generated $1 million in sales in its first eight months of operations, a sign that there is business to be had here. The startup points out that this growth has been, in fact, “faster… than both Amazon and eBay in their early stages.”

WeFarm is based out of London, but while the startup does have users out of the U.K. and the rest of Europe, Kenny Ewan, the company’s founder and CEO, said in an interview that it is seeing much more robust activity and growth out of developing economies, where small-scale agriculture reigns supreme, but those working the farms have been massively underserved when it comes to new, digital services.

“We are building an ecosystem for global small-scale agriculture, on behalf of farmers,” Ewan said, noting that there are roughly 500 million small-scale farms globally, with some 1 billion people working those holdings, which typically extend 1.5-2 hectares and often are focused around staple commercial crops like rice, coffee, cattle or vegetables. “This is probably the biggest industry on Earth, accounting for some 75-80% of the global supply chain, and yet no one has built anything for them. This is significant on many levels.”

The service that WeFarm provides, in turn, is two-fold. The network, which is free to join, first of all serves as a sounding board, where farmers — who might live in a community with other farmers, but might also be quite solitary — can ask each other questions or get advice on agricultural or small-holding matters. Think less Facebook and more Stack Exchange here.

That provided a natural progression to WeFarm’s second utility track: a marketplace. Initially Ewan said that it’s been working with — and importantly, vetting — local suppliers to help them connect with farmers and the wider ecosystem for goods and services that they might need.

Longer term, the aim will be to provide a place where small-holding farmers might be able to exchange goods with each other, or sell on what they are producing.

In addition to providing access to goods for sale, WeFarm is helping to manage the e-commerce process behind it. For example, in regions like Africa, mobile wallets have become de facto bank accounts and proxies for payment cards, so one of the key ways that people can pay for items is via SMS.

“For 90% of our users, we are the only digital service they use, so we have to make sure we can fulfill their trust,” Ewan said. “This is a network of trust for the biggest industry on earth and we have to make sure it works well.”

For True and other investors, this is a long-term play, where financial returns might not be as obvious as moral ones.

“We are enormously inspired by how Kenny and the Wefarm team have empowered the world’s farmers, and we see great potential for their future,” said Jon Callaghan, co-founder of True Ventures, in a statement. “The company is not only impact-driven, but the impressive growth of the Wefarm Marketplace demonstrates exciting commercial opportunities that will connect those farmers to more of what they need to the benefit of all, across the food supply chain. This is a big, global business.”

Still, given the bigger size of the long tail, the company that can consolidate and manage that community potentially has a very valuable business on its hands, too.