A market segment you might be neglecting is that of users needing protection
from malicious trolls or stalkers. An email alias of the form you provide is
no protection at all to them, because the troll can follow the instructions
on your landing page to send any number of messages to the same user by
choosing a new alias for each message. An easy solution is to allow the
option of accepting messages only on pre-defined aliases.
If you do that already, it would be good to mention it in
the FAQ.
