Why do websites crash from high volume? Especially when they know they will be getting high volume?

Because they have not figured out yet how HIGH a volume they were going to get.

basically, the site is being cheap and not paying for enough bandwidth, when the people who connect to the site start requesting more downloads of the site than the server can upload you get a ’‘back soon’’ message or some other variation.

they can probably fix it by upgrading, but that costs money and it may not be worth it to them if the traffic spike is only for a short period of time and then the site is dead the rest of the week.

its called cheap=low bandwidth like @poisonedantidote said

The key point in what @poisonedantidote said is that it’s not worth it to upgrade for a temporary spike. They built the system for the volume they handle most of the time. To upgrade to prepare for record high volume that only occurs rarely is expensive, upgrading requires more servers and more connections, and all the work involved in incorporating them into the system.

Now if it happens every month on the first (or whenever people get paid) and it’s a bank, they should bite the bullet and do the upgrade.

Why does your 2-cup measuring cup overflow if 10 of us poor 1 cup of water into it at the same time, even if we tell you we’re going to in advance?

Knowing that it’s going to happen doesn’t magically increase the capacity.

Good point MrItty lol. Thanks guys.