Where it comes from
Konami Digital Entertainment: Yu-Gi-Oh! TCG remains on top with more than 25 billion cards sold (press release repost) Anime News Network (Konami Digital Entertainment, Inc. release dated 16 Jun 2011) · 16 June 2011 Open the original ↗
The line in the source
With 25,175,567,833 cards now sold since 1999,