Oh the mall: propagator of capitalism and poor spelling. This is an especially atrocious example of, well, both.
I'll be a modest, forward-thinking copy editor and accept that, yes, some spelling alterations are just quicker, especially for text messages and apparently for making store-window displays on the quick (or the lamb).
What is not acceptable is if these alterations are of equal length or longer than the original (boi, really?), or if they're just way more difficult to figure out (perhaps I'm retarded, but d8 seemed like a size). Spelling things with numbers is usually just more work anyway.
Actually, I take it all back. This store window sux.