It should be in a 80/20 ratio, where you practice 80% as the normal routine, and 20% of resources are kept for innovation. Though, innovation is indeed a burning need, and your business can’t sustain without it.
Recently, Google has reduced its resources for innovation, and being a huge organization, I think it is an intelligent move. As, you already have a BIG company to manage and to keep that running smoothly you need to do what you have *innovated already*. But, on the same hand, innovation comes out of the box in such big companies.
You may refer Inc. columnists advice on finding the right amount of experimentation/innovation for your business HERE.