Costco is one of my favourite retailers. They also partner with Aeroplan to a limited extent. You can’t earn points for purchases in-store, but you can with online purchases.
Until August 20th, you can earn 3x the miles by shopping online. You normally earn 1 mile per dollar spent, so with this promotion, you can earn 3 miles per dollar spent. This promotion is at costco.ca only. It excludes all US locations and costco.com.
If you haven’t already, register your Aeroplan number on the Costco website to be eligible for points. Costco, from my experience, has often had the lowest prices on items as a wholesaler, so it’s nice to earn Aeroplan miles on top of that.
You can also earn points by signing up for a new membership, as well as referring friends to Costco. You and your referred friend get 1,500 miles each when they join as an Executive Member, and 1,000 miles as a regular member.
The interesting thing about shopping online at Costco is that they accept both Visa and MasterCard. At warehouses, they exclusively accept MasterCard (Visa in the US) and previously, American Express.
Since they have a very generous return policy, you can return literally anything that you buy, including expensive items. You’re also able to return items that you bought online at the warehouse.
Not that I ever recommend it (and it really is close to an ethical boundary), but I know a few people who have this to their advantage when needing to meet minimum spends and to earn a few extra miles.
See more about the Costco Aeroplan partnership here.