When one develops a slum, for instance, and even if 20 per cent of land is given for commercial use as incentive in the bargain, it is a deal for the developer. After all, in the space starved city like Mumbai even a small chunk of land in any of the prime location is a rare commodity. The question is if such a business dynamics is a feasible model, why did the developers shied away from making the best of it so far.