[jeffs' widgets]
is the same as jeffs widgets
However,
[jeff's widgets]
would not have shown for
jeffs widgets
if you were only doing an exact match on the terms. jeff and s each become a word according to how Adwords interprets things.
As I said, that's been my experience. The previous response was too highbrow for me ;)
Israel
in literary circles there is disagreement about the best way to write something like jesus's apostles. some would leave off the 's - the rule I've heard is that you should write it the way it sounds- if you pronounce the extra s, write it
but of course in adwords we have to deal with all the ways people could write it.
just a side note