It's awfully early to gamble that integration with IFTTT will pay off for the partners. You'd be better off providing and maintaining the integration code, and even paying the partners, until you've established IFTTT integration as a must-have feature for any new service. When Pinboard's customers demand IFTTT integration, you'll have the leverage to push a proprietary API. An even better approach might be to work with your competitors to create an open standard for integration, one that you all benefit from.