Check out the Google Small Business Success Stories site. See examples of UK businesses that are using Google products to help reach customers and succeed online.
You can also filter to see Internet Economy Data from the Boston Consulting Group. What value of GDP is brought in by the internet? What will this be by 2015? With more companies engaging with customers online, the Internet is having a significant impact on the economic growth of countries.
Finally, you can also filter by ‘Google eTown Awards' which celebrate the towns and cities whose businesses are growing online and contributing to the future economic growth of their country. eTown Awards are presented to towns that saw the biggest growth in Google AdWords customers over the last year.
You can also find lots of Adwords specific success stories here. Filter by industry or product.