I don't think that it's only advertising. IMO Chrome provides the fastest and smoothest web experience out there. I am not a fanboy. In fact, knowing how much data is being collected by google makes me a bit uncomfortable.
I showed chrome to friends and family. Ex. take my dad - he was accustomed to FF's interface. He is not proficient with computers so once he know something he's very reluctant to change, but once he used chrome for a while he didn't look back. Same for a bunch of my friends and rest of the family. They were simply amazed by the sheer speed of page loads, etc.
DISCLAIMER I don't know about IE, cause I haven't used it for a long time and I didn't let any of my family members use it (well, it was pure evil then).