I wasn't sure if PC Optimum was properly crediting 20 points per $1 spent at stores like No Frills and 10 points per $1 spent elsewhere. The “PC Financial Earn” lines in the PC Optimum app often didn't show any doubles that I recognized, and the time delay between the transaction and the points credit muddled the waters too. I liked the convenience of using Google Pay on my phone to pay for groceries while out and about with A-, since it's easier to keep track of a big phone than it is to make sure my credit cards are in my pocket when we go out. (Also, A- sometimes insists on hanging onto my credit card after she “pays” for things, so that's one more thing to keep track of if I use a card.) If the 20 points per $1 wasn't getting properly credited, though, it might be worth carrying a different credit card that gives me 2% cashback on grocery expenses.

I sat down and made a spreadsheet based on my credit card transactions, calculating the number of points expected. Here's an excerpt:

I made another spreadsheet with the transactions from the PC Optimum site (no CSV export, oh well). Here's another excerpt:

Here's how those two transactions match up with their points, I think.

and

So if my only transactions for the day are at No Frills, I see a doubled points entry, which is easy to verify. If I also bought something somewhere else, the first PC Financial Earn transaction gives me the extra +10/$1 expected for No Frills, and the second PC Financial Earn transaction gives me the 10/$1 points for the total of both credit card transactions.

The math works out. It was just a little difficult to verify when I was scrolling through it on my phone. It would be nice to be able to do three-digit sums in my head… Anyway, I can probably trust it reasonably well, although I'll keep this explanation around in case I need to figure it out again (or in case someone else needs to).

Thanks to the PC Optimum support staff for giving me the benefit of the doubt when I asked for an adjustment! I sent another message undoing that request, so let's see if I can get this properly sorted out.