Within your company you likely have employees with diverse skill sets. The idea of cross-pollination is to bring these people together, allowing their knowledge and skills to influence each other. Cross-pollination can expose employees to different ideas and new ways of thinking. That in turn can only make your company stronger and more productive.
To encourage cross-pollination, some businesses will assemble a team of people from various disciplines. For instance, instead of having just the engineers develop a new piece of software, the business will bring in sales people and marketers to give their input. All of them approach the same idea with their own perspectives. Like anything else in business, this isn't a guarantee of success; the cross-pollinators could just stick to their own views and reject everything else. However, all of those different backgrounds coming together on a project can lead to extra innovation.
Cross-pollination can also work by sharing ideas across different departments or offices within a business. For example, a company might implement ideas that have been successful in America in an overseas office. Some companies increase this kind of cross-pollination by rotating employees between offices and departments, thereby exposing them to more ideas and methods.
