[styfle]

There was a fund raising website written 15 years ago that a team I was on was responsible for (I never actually worked on it).

There were fraudulent credit card donations for $1 which became really obvious when the zip code was garbage.

The “solution” was to disabled the credit card page until the month of the fund raising event when it was enabled again in hopes of the scammers would not try during that month.

[CapacitorSet]

I don't understand, what were the scammers trying to achieve?

[mr_toad]

Trying to validate stolen or generated credit card numbers.

[jacquesm]

That's not always what is going on. In some cases unscrupulous operators will run through large numbers of $1 transactions in order to lower their chargeback rate.

[nicksantamaria]

This sounds interesting - can you explain further?

[jacquesm]

Chargebacks have a cap, if you go over that cap you get fined or lose your merchant account. So in order to dilute the pool they'll make a lot of low $ amount charges usually masquerading as some charity, those will have very low charge back rates so the average charge back %age will drop.

[megaman22]

Maybe hoping there was an affirmative response if the card did go through?