Adsense targeting -- desktop v mobile

[londrum]

here's something i have been noticing for the last couple of months:

whenever i view my website on a desktop the targeting is absolutely awful. the ads have absolutely nothing to do with the page. some of them are obviously interest-based, but a good half of them just seem to be totally random.
but when I view exactly the same page on my phone or a tablet, the targeting is absolutely spot on. the ads match the page perfectly.

i've tried deleting the cookies on my PC and doing everything anonymously, and viewing it with another PC entirely, but all I get is the same old lousy ads on a desktop.

I can't work out why the the ads would differ so much on a PC, tablet and phone when the content is identical.

is anyone else seeing the same thing?

[IanCP]

An interesting observation. It seems illogical at first, but I would be very interested in a cross section of experience from others. No I don't have a phone or tablet - I do have a dumb phone which makes phone calls and sends texts - nothing else.

[IanTurner]

Yesterday I was thinking that my ads were much more on topic on the desktop.