The sources of innovation can vary, with users, suppliers, and manufacturers playing key roles in different industries. By analyzing historical data, it was found that users are often the main innovators in fields like scientific instruments and semiconductors. Economic incentives play a big role in determining who innovates, with firms choosing to innovate when the potential profits are high. This can limit innovation to specific functional areas. It's also difficult for innovators to switch roles or profit from licensing their innovations. Informal knowledge sharing can help, but it's like a game of trust. This research provides insights for innovation managers and policymakers.