This might be a simple question, but I am trying to figure out if a customers order was placed through a mobile phone or on a desktop? If I click on the invoice I see "Purchased From" and it only says:
Main Website Store Default Store View Main Website
Then placed from IP: and it shows the customers IP adress, but It never says if it is a mobile device or a computer.
Not any practical out of the box way no. If you have a requirement to know this information then your best bet would be to configure a custom attribute against customers which you can use to store their Browser information.
Then on completion of the checkout, save this against the customer record, so you can review and decide for yourself. It wont be completely reliable of course. For example, I'm connected via my phone tethering but I would show up as a Desktop user despite using my mobile.
Actually there is, not using magento tho.
If you are using google analytics you can set ecommerce (sales) URLs and track conversion.
In that interface you can filter by mobile or desktop.
I am using the latest Google analytics code which means that Google is already seeing my successful ecommerce transactions. This allows me to get reports by different dimensions (like device, product, traffic source etc)
I believe that version 1.9 has the latest Google analytics code to allow for this out of the box
