Flickr Queston

I've decided to start a weekly cooking challenge on my blog and wanted to provide a place for people to post pictures of the things that they make.

Since I use flickr to get inbound links, I thought I would start a group in Flickr where those can be posted.

I'm just wondering should I have a invitation only group or a totally open group?

I'm leaning towards an invitation only group...what are your thoughts?

Oh, and if you'd like to join in on the cooking challenge, here is the link:
http://www.thebreakfastcook.com/532/cooking-challenge.

Not sure about your Flickr question really but I just commented on your blog post and I'm up for the challenge. How fun! You are so creative...and I love breakfast!

no idea what this is about its late for me ill read again in the morning

What would be your reasoning to make the group exclusive? Are there benefits to either way?