Starbucks changes the rules again.

The new Starbucks reward program oddly mixes even and odd numbers to complicate the rewards system.

The original program (that is, the first program I participated in), gave one star per drink purchase. Since I often arrive with my kids and get them soy milk, that worked well for me. Three drinks => three stars.

The next program, the one that is going away in April, changed that rule to 1 star per purchase, meaning I got 1/3 the stars on those occasions, and even fewer when they got a snack. (My thin as a rail older son likes the double chocolate chunk brownies, and he can use the calories.) So one drink or three drinks or three drinks and two snacks => 1 star.

Here’s one view on the math (via http://fivethirtyeight.com/features/significant-digits-for-tuesday-feb-23-2016/):

If you buy a $SBUX coffee for $2.50, the old system gave you a free reward after 12 coffees; the new system after 25. 50+% devaluation!

— Josh Zumbrun (@JoshZumbrun) February 22, 2016

But here’s my scenario:

• New plan on its face: $62.50 = 125 stars = 1 reward.
• Old – $2.62/venti tea * 12 = $31.44 for reward (I get a refill on my tea when I’m at the store; usually just one refill and then new bags. That $0.50 is actually free, so in some ways I’m getting ~18–24 teas for that $31.44 plus the reward, which I tend to use for a higher-priced item my kids get.)
• New – $2.62/venti tea *  2 stars/$1 = 5 stars divided into 125 stars = 25 teas = $65.50 per reward.

BUT:
In February, I see these other purchases, mostly with my kids (I might have picked up some beef jerky on my own):
11.66
8.72
6.10
6.26
8.08
6.10
5.46
6.75
5.46
6.85
8.28
= 79.72
Old: 11 stars = 11/12 of a reward
New: 79 *2 = 158 stars, or 158/125 or 1.25 rewards.

It remains to be seen where this will shake out, but the Starbucks app does have a history function that tracks both my $25 reloads and my earned rewards. It should be easy for me to see how this shakes out, provided I capture some numbers now. I suppose that tells me what my next post should be!

(It remains to be seen whether my $2.50 purchase will be 4 stars, 5 stars, or 6 stars. I’m supposing it’s in the fine print somewhere. Let’s take a look…. My 2.62 purchase will evidently earn 5.24 stars – change counts. That’s not trivial: thanks, Starbucks!)