Ask HN: Why credit cards despise sub $1 transactions?

I signed up for a Google API paid account about a year ago. I use their API search console to determine how prevalent an IP registering to my service is. If there are too many results, they don't get the freebie and are told why. If there are few results, they get the freebie and never know they were checked.

So my services isn't all that popular apparently, and I only manage to rack up $0.05 to $0.25 in API charges per month.

Google for some reason decides to charge me in those amounts, every month. (Here's another question, doesn't google make $0.00 on a transaction below the minimum credit card fee?)

And every month, my credit card goes inactive, I get a phone call from security asking me if I "know anything about this Google charge?". I say yes. They re-instate my card. I hang up the phone. Sure enough, the entire process repeats itself the next month.

I am with PC Financial Mastercard in Canada, if that makes any difference?