. . . and why I don't think they work.
Its pretty easy really. I don't think they work because of a lack of actual advertising. One thing that I don't think Apple does and it seems all that Microsoft is doing is attacking the opposing platform. It seems that Apple attacks Microsoft by pointing out what they have and Microsoft doesn't. The new Microsoft advertisements don't even mention anything about Microsoft.
The most recent commercial only mentions two brand names, Dell and Apple. It mentions Apple to say how expensive the 15" laptop is, and then she goes on to purchase a Dell that has a 6" screen or something stupid like that. So, I guess my question is why not compare like devices at least? She could have easily gotten a new Macbook for her $1700 budget, but instead settles on a Dell?
To end this post I will say that anyone who has used a Dell for work, which is probably the large portion of Americans at this point, would never purchase one for personal use. They suck, and companies spend a lot of money on them. So, I can say that she has probably never had a job.