And I'm just pointing this out for those who aren't already aware -- C macros and Lisp macros aren't really comparable. C macros are implemented as string subs

And I'm just pointing this out for those who aren't already aware -- C macros and Lisp macros aren't really comparable. C macros are implemented as string substitutions in a separate step before compilation. Lisp macros can make use of the rest of the language features and allow for operations on the abstract syntax tree of the code, opening up things like adding new control constructs, generating boilerplate code, string substitution, and the creation of domain specific languages.