Too Many

A billion of something is a whole lot. It's probably too much. Consider the following examples.

A Billion Astronauts
You wouldn't be able to send all those astronauts into space. We only have a few spaceships in this world, so only maybe 30 of those astronauts could actually go. That's only .000003% of all those astronauts. The rest would be left with unfulfilling careers as garbage men. Maybe we could ship some of them out to sea just so we don't have to watch heartbroken astronauts taking out our trash.

A Billion Staplers
That would mean more than a billion staples. Unless each stapler only gets one staple, but that would be crazier than having a billion staplers to begin with. I don't care if it causes a staple crisis that cripples some poor country's economy, each stapler needs at least 50 staples. This isn't Russia.

A Billion Canoes
The Native Americans understood the concept of keeping in balance with your environment, which is probably part of the reason why they never mass-produced canoes. After all, if you have a billion canoes, how do you have an efficient canoe race? You'd probably have to do individual time trials, and nobody enjoys that.

A Billion Hot Dogs with Mustard
Mustard is an acquired taste. Personally, I'm not a fan. Someone else could have that hot dog instead of me. Maybe there are a billion people in this world who like mustard, but I don't know. I'm guessing a few of those hot dogs would get wasted.