They have a few different promotions going on.
https://www.questrade.com/about-us/programs-promotions
The 'Transfer your accounts for free' promo is the one you want, they'll cover all your transfer-out costs from your existing broker.
Also, when you sign up, don't bother with any of the streaming data packages. Real-time 'Snap quotes' are free, and the TSX gives free real-time Level 1 anyway, IIRC. I only have real time Level 1 streaming because I'm day/swing trading options. I don't even bother with Level 2.