Ask HN: What is the most promising interface for sales assistance services?

When building services in the field of sales/marketing assistance we ran into the 'interface question'.

Building a data backbone containing hyper local data (demographics, housing, crime... on house no level) we thought an API would be the best interface to access the data.

BUT it turned out, that most of the potential users - mainly in Europe - do not know how to use an API. Asking prospects the interface question did not really bring us further, too.

What would you think will be THE INTERFACE in 2017 for such a service?

Would you think the best way would be to connect our data backbone to Salesforce, RelateIQ or like bot-like into Slack, FB Messenger?