Reverse-engineering with Filepicker API
Looks pretty good. Some notes:


(Time.now - 1.day) -> 1.day.ago
"08/08/2013".to_time: I'd be in doubt "is that day/month or month/day?". An alternative to avoid problems with the parsing format: Time.new(2013, 8, 8)
Net::HTTP: IMO this module is a pain to use for common tasks. I prefer something higher-level like the rest-client gem. It does a lot of boring things for you.
response.response['set-cookie'].split('; ')[0]. I wouldn't rely on this space after the semi-colon. Safer: response.response['set-cookie'].split(';')[0].strip
Use do/end for multiline blocks.
JSON.parse res.body Be consistent, use parentheses like you did in the rest of the code.
stats = stats['data']['links.created']: don't reuse variables: links_created = stats['data']['links.created']
request and later req, response and later res: Use more declarative names.