Or more completely: because Pepsi is sweeter, a small quantity of Pepsi tastes better. However, if you asked people to rate based on an entire can of cola, your results would change. Dunno about that, I'm a Pepsi man, because the first place I worked was a gas station that only stocked Pepsi, so it was the first caffeinated beverage I drank in quantity.
This is rather interesting. Growing up in the UK the only place I could ever find Pepsi was at a KFC. McDonalds and most restaurants all have Coke. My first drink of Pepsi was at my friends' house whose father only ever got fast food from Burger King (which was impossible to find in my area of the UK because they use lower quality beef) so drank Pepsi.
As an adult I've found the only relevant things for colas. Coke goes great with white rums and Pepsi goes great with spice rums. Beyond that I'll drink either whenever.
I've often had exactly the inverse experience on trips to northern CA: so many places, I ask for a Coke, and get told that they only have Pepsi. Mind you, in UK pubs these days, if you ask for a Coke, you'll probably get flat Pepsi out of a hose dispenser - flat on account of the violence of its expression.
I'm not a fan of Pepsi at all, in a similar way to how I don't like any of the diet colas - the sweetness is too much, and it being flat only hurts it further, removing some of the carbonic acid.
When I was growing up, asking for a Coke would result in the counter-question "What kind?" Coke was just the general name for any dark carbonated beverage that wasn't root beer. Although I still don't know why root beer was excluded. :-)
Many years ago, back when I was working my way thru high school, my father was a shop manager at a manufacturing plant. One of the perks he had, was deciding what went in the drink cooler. He swore (all day and half the night) that the small bottles of Coke (8 oz or 6 oz) had a better flavor than the larger bottles of Coke did (which were either 12 oz or 16 oz). So, he made sure that there were always 2 rows stocked with the small bottles.
This is from the days when all the bottles were returnable.
I've heard this explanation before, but haven't seen any data from taste tests that include consuming a whole can. It's an interesting explanation, but doesn't seem backed up by data :/
All very well for Coke to say "If you did this, your results would change"... Where's the data?
