Welcome to the Q&A Forum

Hello! We have an API wiki page at http://apiwiki.moz.com that can help and if you need further assistance I recommend posting your question to our dev discussion forum at seomoz.zendesk.com/forums/293196-developer-discussion-group Hope this helps!

I just checked and mine has gone up by 4, so we must be doing something right. Its the first time I've seen it change since I have been a member.

Have you checked that there weren't any well documented algo changes going on at the time? Maybe you were a winner from Penguin or something. Alternatively have you looked to see how the new traffic broke down? Was it all on head terms or was it in the long tail? Did anything else change on the site at the time? Maybe the page load speed went down? I agree it does seem a bit odd but it could just be coincidence. And congratulations on getting all that extra traffic.