In chrome, add the extension "Auto Refresh Plus"

Tell it to auto refresh the website address for the betfair enhanced fixed odds markets

Set it to notify when the text "find out about fixed odds" appears and set auto refresh time to 10 seconds

Leave it running and you'll be notified when the enhanced market appears.

Its probably got uses for other bookies sites and you can also use it to be notified when items appear in stock in online stores which were previously sold out.