Typography
The web doesn’t provide an ideal reading situation. Low-contrast monitors with matching slow refresh rates make it work to read on-screen, and even when a user has an optimal display, the structure of the web encourages a degree of scanning and link-hopping. To compensate, we spend hours figuring out clever ways to make our content easier to read: we break long passages of text into shorter chunks, use subheaders to facilitate scanning, and—frequently—agonize over the byzantine tangle of cross-browser compatibility to make sure that our text displays the way we want it to.
PROVIDING HELPFUL CUES
Given all that, it would be a shame to diminish the relatively simple tool we have in punctuation marks.
Typography, at the root, is all about providing as many helpful cues for the reader’s eye as possible. Punctuation marks, like fonts, have undergone a process of natural selection to make sure that they do just that.
Curly quotes are curly in part because they make it instantly clear if you're at the beginning or the end of a quotation, and partly because they smoothly guide the eye into the passage:
"Omit needless words."
“Omit needless words.”
Correct em dashes likewise draw the reader’s eye smoothly from clause to clause without the visual break of a clunky double-hyphen.
Primitive punctuation looks sloppy--why not be stylish?
Primitive punctuation looks sloppy—why not be stylish?
Particularly in a medium that invites a thousand distractions, anything that we as web developers can do to maintain the reader’s focus and keep her eyes moving smoothly over our text can only benefit our content.
A matter of style
Ill-formed punctuation detracts from an otherwise well-designed website in subtle but accumulative ways. Single primes acting as apostrophes and double hyphens serving as em dashes belong to the era of grey backgrounds and monospaced default fonts.
TIME TO GROW UP
Ever more sophisticated specifications and browsers have enabled web developers to create more appealing web interfaces, and web design standards have risen accordingly.
Conscientious graphics designers don’t let incorrectly optimized or sloppily cropped versions of their images go live, nor do good copywriters or editors publish websites with typos or grammatical errors. Nor should web developers who aspire to professionalism leave the typographical details of their sites incomplete and unconsidered.