Unless you have *directional* tread pattern tires (which would be
indicated by a label and arrow showing required direction of rotation on
the sidewall), you should either move fronts straight back and move the
rears to the opposite side on the front *OR* move the backs straight
forward and move the fronts to opposite side on the rear.  Choose *one*
of those two and do that pattern consistently over the life of a given
set of tires.  That way, over the series of rotations that you will give
them over their life, you maximize the evening out of irregular wear
patterns, which is the purpose of rotating them (along with reducing
likelihood of their becoming noisy and/or non-optimum handling).  (If
you think about it, with one of those two patterns, each tire will have
at least one turn at every position over its life.)

Your tire dealer is either grossly incompetent *OR* they noticed that
your tires have directional rotation tread.

If you've not rotated your tires over the first half of their life, you
won't gain optimum tread life by starting to rotate at this late date,
but you will gain something.  If they rotate them for free, then it's
worth doing.  If they charge you for it, then it's questionable whether
you will have a net savings.  To really benefit from rotation, it should
be done every 5000 to 7000 miles.  For most people who take decent care
of their cars, a rule of thumb would be either every oil change or every
other oil change depending on what you use for the change interval.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')