6. Exclamation Marks

The exclamation mark is an almost completely spurious piece of punctuation. Its purpose in normal writing is to attract attention to a statement.

But in commercial texts, where every line is supposed to deliver a simple, clear statement, adding exclamation marks should be unnecessary. Either your line of copy will stand up in its own right, or not at all. If you add exclamations, you will probably succeed only in making your writing look tacky.