@iamnarendrasingh I'm glad you got the note! The sticker program was another one of @LN's great ideas and she wrote the note as a thank you from the entire ODK community, myself included.
@LN has been sending out stickers in batches as she has the time. The first batch went to interns who filed out the internship survey and the second batch is going out to a handful of contributors around the world so we can test our international shipping process.
In the next few weeks, we will announce a more formal process for contributors to request stickers, so stay tuned for that!