It depends on your need. In this case small INI files on a central server are fine, even a monolithic file is fine as long as the total user base and concurrent login count is small. If it doesn't matter so much whether you are alerted the first time someone logs in or the third time that they log in then it doesn't warrant significant additional coding complexity which has to be maintained. If you do need to know first time then validate by reading back and re-doing the WriteValue() in a simple loop. Definately use INI files though, flat text files are more of a problem and require more complex coding from the start.

Sometimes good enough is all that is needed to do the job.