Uhh, I've never seen a Microchip ad before. I believe Atmel spends a lot more money advertising. They give deals to universities and put ads in the Mouser catalogs. PIC micros pack a lot of peripherals on their devices. Atmel does, also, with the AVR devices but PIC was doing it first. So there are more tutorials and books for PIC. Historically, Microchip has been very friendly to hobbyists. Until recently, you could sample many of their devices, completely free. Only recently have they started to charge shipping cost. Also, AFAIC, Microchip's website and distribution network blows Atmel's out of the water.
There ARE a lot more makers than Atmel and PIC. The 8052 is another fine processor which has all the facilities of the PICs, plus more speed and a better architecture....
In terms of their 8-bit ucontrollers, Atmel and PIC are very similar. They are available in very low pin count models in DIP packaging, with various assortments of onboard peripheral functions. That is the only reason why I compared those two, specifically. They are a very natural comparison, and there's not a lot else that I know of that really falls into all of those categories. If 8052 has all the facilities, as you say, then I was not aware of that. I actually thought they had integrated timers and memory, only, and only available in high pin counts.
Doh! I just saw my first Microchip advert. In the upper right of this window. :)
PIC is easier to spell. Performance and cost look about the same where I've looked.