The Toronto Santa Claus Parade needs to mix things up year after year, to ensure they don't rerun the same parade. Often, they'll simply redesign an existing float.
For example, here's the Yahoo! float that was in the parade the last few years. As you'd expect from Yahoo!, it's a young girl on her laptop.
Now that it's a Duracell float, that same girl is gently fondling batteries and playing with battery-operated toys.