How to pass complex model from client to server?

I have some data "Foo" that I want to pass from the browser to the server and retrieve predicted statistics based on the information contained within foo.

$.ajax({
      type: 'GET',
      url: "/api/predictedStats/",
      data: "foo=" + ko.toJSON(foo, fooProperties),
      contentType: 'application/json; charset=utf-8',
      dataType: 'json',
      success: function(data) {
        return _this.viewModel.setPredictedStats(data);
      },
      error: function(jqXHR, statusText, errorText) {
        return _this.viewModel.setErrorValues(jqXHR, errorText);
      }
    });

I created a predicted stats controller and get method taking an argument of Foo.

public class PredictedStatsController : ApiController
{
    public PredictedStats Get(Foo foo)
    {
        return statsService.GetPredictedStats(foo);
    }
}

Sticking a breakpoint on the Get method I see the Foo object is always null. There are no errors thrown from the webapi trace logging just the following lines.

WEBAPI: opr[FormatterParameterBinding] opn[ExecuteBindingAsync] msg[Binding parameter 'foo'] status[0]  
WEBAPI: opr[JsonMediaTypeFormatter] opn[ReadFromStreamAsync] msg[Type='foo', content-type='application/json; charset=utf-8'] status[0]  
WEBAPI: opr[JsonMediaTypeFormatter] opn[ReadFromStreamAsync] msg[Value read='null'] status[0]   

I've no problem sending the data via a post to the Foo controller to create the Foo object on the server so I can say there's nothing wrong with the json created clientside.

Looking in fiddler the resulting Get looks like the following where jsondata is the object foo.

GET /api/predictedStats?foo={jsondata} HTTP/1.1

Is this even possible or am I going about this all wrong?

Thanks Neil

EDIT: I feel like I almost got this working with the following

public PredictedStats Get([FromUri]Foo foo)
{
    return statsService.GetPredictedStats(foo);
}

The object foo was coming back fine but no properties of Foo were being populated properly.

In the mean time I've resorted to using a POST with near identical data just dropping the "foo=" and this is working just fine.

I'm not sure whether the POST or the GET should be used in this case but that would be interesting to know.

I also found this http://bugs.jquery.com/ticket/8961 which seems to suggest you can't attach a body to a GET request with jquery so POST is probably the only sensible option