I tried Parcel Delivery and it worked, i can click on the little button on the right site in gmail and a cart shows up in google now. However Order doesn't seem to work for me at all. I used the google markup tester and it said its fine. I also do have the button on the right site in gmail, but no cart shows up in google now. Since i can't figure out what i'm doing wrong i know ask you this question.
This is the Code i use. It is the code you provide on your site, except that i changed the orderDate since that caused a problem while i tested Parcel Delivery.
<div itemscope itemtype="http://schema.org/Order">
<div itemprop="merchant" itemscope itemtype="http://schema.org/Organization">
<meta itemprop="name" content="Amazon.com"/>
</div>
<meta itemprop="orderNumber" content="123-4567890-1234567"/>
<meta itemprop="priceCurrency" content="USD"/>
<meta itemprop="price" content="539.00"/>
<div itemprop="acceptedOffer" itemscope itemtype="http://schema.org/Offer">
<div itemprop="itemOffered" itemscope itemtype="http://schema.org/Product">
<meta itemprop="name" content="Samsung Chromebook"/>
<meta itemprop="sku" content="B009LL9VDG"/>
<link itemprop="url" href="https://rads.stackoverflow.com/amzn/click/com/B009LL9VDG" rel="nofollow noreferrer"/>
<link itemprop="image" href="http://ecx.images-amazon.com/images/I/81H-DO3qX0L._SX522_.jpg"/>
</div>
<meta itemprop="price" content="249.99"/>
<meta itemprop="priceCurrency" content="USD"/>
<div itemprop="eligibleQuantity" itemscope itemtype="http://schema.org/QuantitativeValue">
<meta itemprop="value" content="2"/>
</div>
<div itemprop="seller" itemscope itemtype="http://schema.org/Organization">
<meta itemprop="name" content="Samsung Marketplace Store"/>
</div>
</div>
<div itemprop="acceptedOffer" itemscope itemtype="http://schema.org/Offer">
<div itemprop="itemOffered" itemscope itemtype="http://schema.org/Product">
<meta itemprop="name" content="Google Chromecast"/>
<meta itemprop="sku" content="B00DR0PDNE"/>
<link itemprop="url" href="https://rads.stackoverflow.com/amzn/click/com/B00DR0PDNE" rel="nofollow noreferrer"/>
<link itemprop="image" href="http://ecx.images-amazon.com/images/I/811nvG%2BLgML._SY550_.jpg"/>
</div>
<meta itemprop="price" content="29.99"/>
<meta itemprop="priceCurrency" content="USD"/>
<div itemprop="eligibleQuantity" itemscope itemtype="http://schema.org/QuantitativeValue">
<meta itemprop="value" content="1"/>
</div>
<div itemprop="seller" itemscope itemtype="http://schema.org/Organization">
<meta itemprop="name" content="Google Store @ Amazon"/>
</div>
</div>
<div itemprop="priceSpecification" itemscope itemtype="http://schema.org/DeliveryChargeSpecification">
<meta itemprop="price" content="10.00"/>
<meta itemprop="priceCurrency" content="USD"/>
</div>
<link itemprop="url" href="https://www.amazon.ca/gp/css/summary/edit.html/orderID=123-4567890-1234567"/>
<link itemprop="orderStatus" href="http://schema.org/OrderStatus/OrderProcessing"/>
<link itemprop="paymentMethod" href="http://schema.org/CreditCard"/>
<meta itemprop="paymentMethodId" content="**** **** **** 1234"/>
<meta itemprop="orderDate" content="2014-12-02T23:30:00-08:00"/>
<meta itemprop="isGift" content="false"/>
<meta itemprop="discount" content="0.97"/>
<meta itemprop="discountCurrency" content="USD"/>
<div itemprop="customer" itemscope itemtype="http://schema.org/Person">
<meta itemprop="name" content="John Smith"/>
</div>
<div itemprop="billingAddress" itemscope itemtype="http://schema.org/PostalAddress">
<meta itemprop="name" content="Google"/>
<meta itemprop="streetAddress" content="1600 Amphitheatre Pkwy"/>
<meta itemprop="addressLocality" content="Mountain View"/>
<meta itemprop="addressRegion" content="CA"/>
<meta itemprop="addressCountry" content="USA"/>
</div>
<link itemprop="orderStatus" href="http://schema.org/OrderInTransit"/>
</div>
Google Now only displays parcel delivery cards, not order markups.
In Google now, if you go to settings->cards->Gmails-> Show cards based on Gmail ---- you see option for Package tracking only.
Hope that helps!