Unexpected Letter From Google Adsense

For me, received a letter is a rare thing. No one had ever sent a letter for me except to collect the internet bill. But last October I received a letter from Google! yes Google. Precisely Google Adsense with a colorful envelope typical Google. The letter contains a voucher to use Google's AdSense service valued at Rp 400.000. Waw it big enough quantities. Offer is valid through November only. Unfortunately because of busy looking for work without felt in November has come, the voucher expire. Never mind, thank you Google for your attention