I believe your niche site will do well over time... all the best!
I hope you could use your E-Profile to promote your site in our community - you can 'drop' your E-Profile as business cards in the Intelligence section, and also in events when you RSVP to an event or post an event!!
We are still very new and will continue to grow - if you like it - please invite your professional contacts to join us! But don't tell Xing just yet... ;-)
have a great weekend! Jesse