API Extension: check whether eBay username is registered

[ludwigschubert]

Hallo Mario,
I'm currently developing a companion application for your online service and would like to ask you, whether a small addition to the Gixen API could be made:

After a user enters his eBay username in my app I would really like to check with your server whether this username is a registered Gixen user that can use the API.

This would make a nicer user experience if the eBay username can be checked right after it's entered... even before the suer gets to the password field.

It's a minor, subtle user experience thing, but imho worth the effort.
Do you think that's unreasonable?

Regards,
Ludwig