For portal users there is only the mail domain that can be used to group users when looking at votes and comments. It is also hard to see what company the user works for if the mail domain is inconsistent.
We have a lot of customers in China and for some reason they use a lot of different mail domains that are not connected to the company mail domain. In other words it is very hard to see which of our client companies they work for.
An additional information field for each user with company name would help and could also be used when checking votes by company and not only by user. The mail domain does not help here.