http://www.fcac-acfc.gc.ca/eng/resources/publications/paymentoptions/ccfees/ccfees-3-eng.asp
キャッシュアドバンス扱いになるものは、クレジットカードで「キャッシュに準じるもの」を買ったときなんだそうです。これには、電信送金、郵便為替、トラベラーズチェックのほかに「ギャンブル・トランザクション」というのがあって、宝くじはこれに当たるのだと思います。すべてのカード会社がそうするわけではないみたいですが。
Cash-like transactions
Cash-like transactions are special item purchases that some credit card issuers treat the same way as cash advances.
Cash-like transactions can include:
・Wire transfers: money sent from one bank to another electronically;
・Money orders: a type of payment issued by a bank at your request, which is considered more reliable than a personal cheque because the amount is prepaid;
・Traveller's cheques: prepaid cheques in fixed amounts that allow the person signing them to pay for things;
・Gaming transactions: these include placing bets and buying casino gaming chips and lottery tickets.
If you are not sure whether a particular transaction will be treated as a cash advance or as a purchase, contact your credit card issuer.