I am not sure if I mentioned it, but when you send nengajo New Year’s cards, most of the standard cards you can buy have a lottery number printed on the back. You then hold on to all the cards you received until mid January, when the winning numbers are drawn, and then you have half a year’s time to go a post office and claim any prizes you have won.
Prizes start from sheets with stamps (it is a post office lottery after all) for correct two-digit numbers, local specialities for the correct 4 digit number (this year you could choose among specialities from 38 of Japan’s provinces) and the first prize for 6 correct digits are a holiday trip, household appliances (TV, washing machines, etc), or 100.000 YEN.
These are the lucky numbers for this year. Unfortunately, I was only 75% lucky: I had the 648 of the middle prize, but no 9 in front of it… Of course, since I only received seven cards, this was to be expected. Friends told me that they send around 100 nengajo each year, which means they should receive just as many in return. In that case, it is easier to be lucky, no?