While trying to sign up for a business credit card on American Expresses website I encountered a complete show-stopper. The street address field only allows 20 characters. But what if my address is longer than 20 characters? According to their help text I’m supposed to use abbreviations to make it less than 20 characters. But wait, I haven’t even gotten to the part of my address where I can use abbreviations.
Usability recommendation: Allow your users adequate field lengths to collect the type of data you intend to collect. Be generous with this. It’s inexpensive to store a few extra characters in a database, but it’s very costly to turn users away from your product/service.