This has not been fixed yet. The header required is Content-Encoding: gzip, as @dan_royo said, not “content-type: application/gzip” as we receive now; and the extension “.json.gz” is also not enough. Please take a look at the headers for a cURL request to such a stats file, which contains the Accept-Encoding: gzip request header as it should, but the response headers are missing the Content-Encoding: gzip header:
* About to connect() to ton.twimg.com port 443 (#38)
* Trying 104.244.43.71...
* Connected to ton.twimg.com (104.244.43.71) port 443 (#38)
* skipping SSL peer certificate verification
* SSL connection using TLS_RSA_WITH_AES_128_CBC_SHA
* Server certificate:
* subject: CN=*.twimg.com,OU=Twitter Security,O="Twitter, Inc.",L=San Francisco,ST=California,C=US
* start date: Apr 22 00:00:00 2016 GMT
* expire date: Apr 27 12:00:00 2017 GMT
* common name: *.twimg.com
* issuer: CN=DigiCert SHA2 High Assurance Server CA,OU=www.digicert.com,O=DigiCert Inc,C=US
> GET /advertiser-api-async-analytics/[sensitive-information].json.gz HTTP/1.1
Host: ton.twimg.com
Accept: */*
Accept-Encoding: gzip
< HTTP/1.1 200 OK
< Date: Thu, 12 May 2016 10:41:28 GMT
< Server: Apache
< content-md5: 1Z5PbdZV7Qn7TQyMGn9cfQ==
< content-type: application/gzip
< etag: "1Z5PbdZV7Qn7TQyMGn9cfQ=="
< expires: Thu, 19 May 2016 09:00:28 GMT
< last-modified: Thu, 12 May 2016 08:55:16 GMT
< x-connection-hash: 0170bcd18baf77858fc355817d55560a
< x-response-time: 9
< x-ton-expected-size: 525
< x-ton-expires: Thu, 19 May 2016 08:55:16 GMT
< Cache-Control: max-age=31536000
< Content-Length: 525
< Accept-Ranges: bytes
< Via: 1.1 varnish
< Age: 6060
< X-Served-By: cache-tw-fra1-cr1-16-TWFRA1
< X-Cache: HIT
< X-Content-Type-Options: nosniff
<
* Connection #38 to host ton.twimg.com left intact
@hwz: Could you please send this further to the technical team to fix? Thank you!