I've looked all over for some documentation on this, but haven't found it. Some posts reference a user-agent string:
I had assumed there would be an API or something. More generally, how does ANY rss feed reader/aggregator (like Bloglines, etc) report subscriber numbers to Feedburner?
I'm working on developing a new app that would need this functionality.
Thanks for your help! Brian
As you discovered in your link, you put the subscriber count in your user-agent, then you contact the Feedburner Support Group and tell them what format you will be using.
The consensus format is something
User-agent: Service Name (http://example.com/service/info/; ### subscribers ; [optional feed identifier] )
The optional feed identifier is typically used if you run several different services, and fetch the feed separately for each one; e.g. if you have a mail service and a web-based reader service, with different subscribers, then you might either use:
User-agent: SO Agg/1.3 (http://example.com/SOAgg ; 5000 subscribers ; feed-id=mail-134 )
on request for the mailer, and
User-agent: SO Agg/1.3 (http://example.com/SOAgg ; 2000 subscribers ; feed-id=web-134 )
on the request for the website; or use
User-agent: SO Agg/1.3 (http://example.com/SOAgg ; 7000 subscribers ; )
if your system makes only one request for both services...
You will usually need to specify what IP addresses are authorised to request the feed with that user-agent, as well.