Sometimes a large company can't make money by offering more add-on services, but they can offer more services (not minor features) to customers from a partner/outside provider. This gives them two advantages - retain customers this way and make some money through a shared service deal with the smaller service provider. So if your idea could be suitable for something like this, you can present this idea as the possibility of becoming the partner to them. This only works if you have the credibility and you can actually build it out and make it work. They can sometimes even fund you to develop this. Always the danger that they "steal it", or more likely, don't get excited about it (probably because it's on their internal list of things they thought of, but can't get to).