To make this work you need to first authenticate in order to obtain a valid SID
for a given google site which can be used to access data. Here's how you could achieve this:
class Program
{
static void Main(string[] args)
{
using (var client = new WebClient())
{
// TODO: put your real email and password in the request string
var response = client.DownloadString("https://www.google.com/accounts/ClientLogin?accountType=GOOGLE&[email protected]&Passwd=secret&service=trendspro&source=test-test-v1");
// The SID is the first line in the response
var sid = response.Split('\n')[0];
client.Headers.Add("Cookie", sid);
byte[] csv = client.DownloadData("http://www.google.com/insights/search/overviewReport?q=test&cmpt=q&content=1&export=2");
// TODO: do something with the downloaded csv file:
Console.WriteLine(Encoding.UTF8.GetString(csv));
File.WriteAllBytes("report.csv", csv);
}
}
}