Sometimes certain information is kept quiet. Or, it is simply a case of missing or lacking communication. Unfortunately, when your customers or consumers have to figure out your limitations on their own, they will not be very appreciative of your services by the end of it. This applies to the online world as well in a big way. Perhaps even more so, as online you really do have the time and the space to communicate these things up front.
Online forms is an area where this comes into play often. Who hasn’t had the experience of diligently filling out an online form, only to find upon submission that your information is not going to be accepted? Perhaps you live in a country that is not able to participate for a various number of reasons. Or you don’t have the right account to process your transaction. Either way, if you had been told about such factors before getting to the form you would a) not have wasted your time and b) not be feeling frustrated at the company/organization who failed to communicate with you.
The point is, let people know about the important limitations that will affect their experience with you and your brand. If you’re really good… you can find a way to take a limitation and make it a positive talking point.