I was watching Dragon's Den and they had a pitcher for a service called CardSwap.ca on the show. The site buys people's unused gift cards, and/or sells you gift cards. As you buy gift cards you accumulate points that you can use (when you have enough) to buy other gift cards, or just convert to PayPal cash.
For the last few months I've been using it and it's been great. You can use Chapters/Indigo gift cards with Kobo to buy e-books, or with Chapters/Indigo/Coles (online and off) to buy e-readers.
I've averaged about 9% savings so far, and it's a way of saving money on agency books (or magnifying savings on non-agency books, if you're using a discount code). To Kobo it's just a gift card, the fact that you realised a savings by buying it is neither here or there as far as they're concerned.
What I did was start bulking up on gift cards to buy first my Glo, then again to buy a Glo for my girlfriend's daughter, and then again to pre-order a Kobo Arc for my girlfriend. I suppose if you preferred to buy your readers at Future Shop or Best Buy you could buy their gift cards for the readers, but only Chapters/Indigo gift cards can be used for e-books.
Amazon.ca is on there too, but because you can't buy e-books or e-readers from Amazon.ca (or use those gift cards on Amazon.com) that's not useful to e-book enthusiasts.
If you're going to buy e-books from Kobo anyway, you might as well do it this way and get the bonuses for first buying the gift cards. I buy them right before I anticipate spending them, so I'm pre-paying for a short-term use (rather than a long-term use).
So far in buying two Glo readers, a Kobo Arc, and two sleepcovers, and a couple of e-books, I've saved about $70. Not a huge savings given I had to spend over $700 (after tax) to get that savings, but if you're going to spend the money anyway you might as well get whatever savings you can get.
Mods: I'm just a consumer of this service, so this is not meant to be promotional in any way. I'm not getting any bonuses or kickbacks from CardSwap for recommending them, either. In fact, since CardSwap is a supply/demand driven service, it's actually detrimental to me to let anyone here know about it as it reduces the supply of Chapters/Indigo gift cards of their site, and the most popular gift cards on CardSwap (Tim Horton's, Canadian Tire, etc.) pay out the smallest numbers of points to purchasers. But I've benefited from the recommendations of other Mobileread users, so it's only fair I return the favour.