Not sure about the validity
You could have lumped microwave sales in with electric oven sales in the 1980s, and said sales of home cooking devices had gone up. But in fact most microwaves were bought by people who already had a cooker, so the sale of microwaves gave no clues at all to the health of the thermal cooker market.
I'm not sure it is valid to lump netbooks in with the rest of the "mobile market" and assume you are learning anything.
I have one, running Suse 11.1, and I use it for very different things to my flaptop. I use it as a web tablet, and as a replacement for my dab radio. And for VOIP
Perhaps sales of netbooks should be lumped in with DAB radios? or with cordless phones?
I think these numbers really mean:
* a lot of people bought into a new product category
* in other news, laptop sales are down
- Updated Zucker punched: Google gobbles Facebook-wooed Titan Aerospace
- Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
- Windows 8.1, which you probably haven't upgraded to yet, ALREADY OBSOLETE
- Mounties always get their man: Heartbleed 'hacker', 19, CUFFED
- Android engineer: We DIDN'T copy Apple OR follow Samsung's orders