To begin with: one of the benefits may include more sales and access to other markets. That also means access to new customers, and when talking about Europe, it may be especially important as many countries even outside EU have collaboration agreements and access to the market in one country may easily mean expanding the customer base in another
One can hardly neglect the access to the local talent, too. This may be especially true in case of global shortage of talents, like it is the trend in the IT industry. You can easily learn about the environment and status of IT industry in the area, including the level of expertise, work ethic, and the price range.
Furthermore, alhtough it is not always a crucial point, but when arriving on a market which have high demand of resources that would be valuable to your business, it is not the worst idea to get there before your competitors and position yourself first.
Finally, if your goal is not to be a part of a market share customer-wise with opening a new branch, one of the benefits is also lowering the operational costs. Hiring local people who are well aware of legislation and business etiquette is a big plus. And they will do their best to come up with ideas how to align the working hours with your time zones for more efficiency and great business results.