(a) They save time required in separate drafting of such
routine or stereotyped letters.
(b) Incoming letters requiring routine replies can be
speedily answered with the help of form letters.
(c) They reduce the cost of producing correspondence.
However, Form letters also suffer from several
disadvantages, viz., these cannot be varied to suit individual cases;
the language of such letters lacks the personal touch and often
impression on the recipient; and the style of such letters is often
found to be stilted and officious.