I thought this (apostrophe) was in discussion recently and a quick search in archive gave many threads....this was not the one I was looking to add to....but it will do!

"EAGLE-eyed bargain hunters have rushed to social media sites to lampoon Myer for a grammar clanger in seven-storey-high banners erected across Australia."

Oh the shame!

link to picture

Myers recently reopened after the Christmas break, with a new campaign featuring the slogan, “Early bird get's the right size”.

As you notice... the apostrophe isn't necessary...as did lots of other punctuation enthusiasts across the country.