What you smokin' murko? There's a tiny contest button which is hardly intrusive and if you click it it tells you exactly what it is (a contest) and what it will do BEFORE it changes your personal message.
Direct quote from the window which appears as soon as you click the button:
quote:
The rule is simple: click on the image and find the prizes! They are all "hidden" in specific coordinates that were randomly generated at the beginning of the contest. Pick a spot, click, and you will be instantly notified if you won the prize or not. You can play as many times as you want for the duration of the contest. The only requirement is to let Messenger Plus! add a promotional tag in your personal message while you play, that's it.
At that point you can choose whether you wish to play or not. Any sentient being capable of reading would read the clear, plain writing and known exactly what it is: the opportunity for Messenger Plus users to win real prizes, as many already have, in exchange for
only a link being placed in your personal message for the duration the game is played.
If you don't want to win prizes just click the cancel button and that's all there is to it, what's the problem? You are either a half-wit or a douche.