I drink a lot of lemonade and I make it very simply: one cup lemon juice, one cup Splenda, and then water to two quarts. This is barely more work than a powdered mix (it's three steps instead of two), and if you get the lemon juice at CostCo, it's cheaper than sugar-free lemonade powders. (If you prefer sugar to sugar-substitute, it's not really cheaper, but it's not really more expensive, either.) It tastes better, and you get to control the sweetness to your taste. Plus it's probably healthier. It's one of those things where I wonder why people use the mixes... but probably it's because if you buy lemon juice in the supermarket it's a fair bit more expensive, so they don't re-do the math after considering CostCo prices.
Today, in the kitchen at my office, I was mixing some of it up while my boss was microwaving his coffee, and he asked me what I was making. He wondered if it was very sour. I had to explain to him that it was just lemonade, not some obscure beverage he's never heard of, not some weird meal-substitute plan, not some unfamiliar medication, but ordinary lemonade. Now, my boss is not some 21-year-old who thinks that Peter Jackson ripped off J.K. Rowling; he's older than me and usually one I expect to know how things "used to be done". How he could not recognize the most basic recipe for lemonade is beyond me.