What I have learned building products for the European market
For the past three years, I have worked for a European division of a global FTSE listed company.
As I have helped build out new products and features, learned the feedback coming from users and employees, I have gained an understanding of some of the differences between users in this market.
To sum up in a single sentence:
The United Kingdom are extroverts, Germany are introverts, and everyone else is somewhere in-between.
To expand, German users are a lot more privacy conscious. Creating site accounts, uploading content… they are not all that keen on performing these kinds of actions.
Comparatively, users in the UK are far more likely.
Elsewhere (Benelux, France, Italy) users sit somewhere in the middle. If anything they view closer to German patterns than the UK.
This means having to alter your approach if you operate a service where you act as some-kind of middleman such as a job recruitment aggregator. German users will not apply for a job on the recruitment site. Instead, they want direct contact details or to be forwarded to an application form on the website of the company hiring.
As to the other parts of Europe (Scandinavia, Eastern Europe, the Mediterranean region), I have not yet built products specifically for them but the data I have seen suggests Eastern European users are more willing to engage like the UK.