Maximizing usage of Parallel.For or Parallel.Foreach loops

Question

I have a structure of nested Parallel.For and PLINQ statements in my small console app that basically performs network-bound operation(performing http requests) like following:

a list of users is filled from DB where then I do following:

Parallel.For(0,users.count(), index=>{

// here I try to perform HTTP requests for multiple users

});

Then inside this for loop I perform a plinq statement for fetching this user's info via HTTP requests.

So that now in total I get two nested loops like following:

Parallel.For(0,users.count(), index=>{

// Some stuff is done before the PLINQ statement is called... 
newFilteredList.AsParallel().WithDegreeOfParallelism(60).ForAll(qqmethod =>
    {
        var xdocic = new XmlDocument();
        xdocic.LoadXml(SendXMLRequestToEbay(null, null, qqmethod.ItemID, true, TotalDaysSinceLastUpdate.ToString(), null));
        int TotalPages = 0;
        if (xdocic.GetElementsByTagName("TotalNumberOfPages").Item(0) != null)
        {
            TotalPages = Convert.ToInt32(xdocic.GetElementsByTagName("TotalNumberOfPages").Item(0).InnerText);
        }
        if (TotalPages > 1)
        {
            for (int i = 1; i < TotalPages + 1; i++)
            {
                Products.Add(SendXMLRequestToEbay(null, null, qqmethod.ItemID, false, TotalDaysSinceLastUpdate.ToString(), i.ToString()));
            }
        }
        else
        {
            Products.Add(SendXMLRequestToEbay(null, null, qqmethod.ItemID, false, TotalDaysSinceLastUpdate.ToString(), "1"));
        }
    });
});

I tried using the outer for loop just as a regular one ,and I noticed that it was performing much faster and better than like this.

What worries me here mostly is that I was checking the utilization of CPU when running the console app like this, it's always nearby 0.5-3% of total CPU power...

So the way I'm trying to perform HTTP requests is like this:

15 users at a time * amount of HTTP requests for those 15 users.

What am I doing wrong here?