Salsa's free Free Burrito – July Promotion, pretty sure it's free to join, can't find any cost:

mex club join | Salsas

Join Mex Club and Get a Free Burrito – July Promotion T&C*

* Please note that your free burrito can only be claimed after you have registered your Mex Club Card. One free burrito redemption per person per Mex Club registration.
10 points (worth $10 of Mex Club points) will be added to your Mex Club Card within 2 weeks after registration.
Not available in conjunction with any other offer. Not redeemable for cash.

Hola muchachos and muchachas,

For every $15 that you spend at any Salsa’s in Australia, you will earn 1 point, which equates $1. These points can be redeemed during your next purchase, or if you accumulate enough points you can get a FREE meal.
But the best thing about the Mex Club is the FREE Birthday Burrito. Members can get a free burrito from any Salsa’s across the country on their birthday. If you’re too busy having a fiesta on the day, you have 2 days before and 2 days after to claim your FREE Birthday Burrito!
How to earn points

Just grab a card from any Salsa’s store and swipe the card during every Salsa’s transaction. You can start earning points, but to start spending your points you’ll need to register your card.
How to register

To officially join Mex Club and start spending your points,you’ll need toregister your Mex Club Card here.
Salsa’s special offers

Once your card is registered we’ll send you an email notifying you of the latest and greatest offers. If you choose to add your mobile number when signing up you could receive even more fantastic deals!