In the tradition of putting the letter "z" instead of "s" on the end of a word, which then makes it in the sarcastic form of the word ex. "guyz" or "gurlz" -- A misspelling in a pseudo-urban speak or spelling puts an ironic flair to the meaning.
"the humans are doing sportz today"
" the game is on" #sportz - if used on twitter
As in the portrayal of the use of the word "Sportz" in the Youtube video "We Like Sportz" by The Lonely Island produced by Andy Samberg