It's a bit of a misnomer. Fidelity Investments offers a 2% cashback card via FIA/Bank of America; that really gives you FIA points, which you can convert to Aeroplan 1:1. Thus, you can get 2 Aeroplan miles per $US. The blog author values Aeroplan miles at 1.5¢ (see comment from 14 April), and you end up with a 3% return on the card.

Whether Aeroplan miles are worth that much to you is an entirely different question, since their award redemption fees are higher than what Americans are used to. I do know that they're pretty good value for short transborder trips.