Google AdSense team updated its email preferences with addition information tips – log in and update your email preferences under the "My Account" tab:
"If you want to be invited to upcoming events like AdSense In Your City? Check the box next to Special Offers to stay up-to-date with giveaways and other special programs in your area.
Want tips from the AdSense team for how to earn more with your AdSense account? Check Customized help and performance suggestions and/or Newsletters.
To help improve AdSense by testing features like new AdSense interface? Check Google Market Research.
Want promotions and key updates for other Google products that can help you grow your AdSense business? Check Information about other Google products and services," informs Google.