Unlock Rewards is a new Android app that promises you a monthly trove of Flybuys points for very little effort on your part. All you need to do is... look at a full-screen ad whenever you unlock your phone?

Who doesn't love to get something for nothing? That's the basic premise for retail rewards cards and supermarket giant Woolworths has stepped up the game in this department. It has unveiled a new rewards card program that gives out more points and more bonus goodies in a bid to compete with its biggest rival Coles. So which program gives you more? Here's a side-by-side comparison of the two supermarket rewards programs.

The vast majority of us shop at Coles and Woolies fairly frequently. Sometimes the choice is made by whatever supermarket is closest, but the two are often located together. Saving a little money is always a good thing, so which rewards program gives the best return?

If you're a member of Woolworths' Everyday Rewards or Coles' flybuys scheme, you'll be used to receiving regular emails promising "special" offers and "bonus" deals that are just for you. But don't delude yourself: 9.5 million Australians are signed up to those schemes.

We're not big fans of Coles' flybuys loyalty scheme -- earning points takes ages and you give up lots of personal information in the process. The recently introduced flybuys Toolbar takes this to a new level of intrusiveness, promising you can earn points "just for surfing the web". Perhaps -- but you'll give up even more information while doing so, and get a maximum of 50 cents a month for the dubious privilege of using an inferior search service.

We've been talking about the new flybuys loyalty scheme quite a bit here at Lifehacker, but I realise that coverage has skipped one relatively central point: whether points are easier to earn under the new scheme than the old one. It turns out that the new flybuys is marginally more generous, but neither offers anything like the level of savings you'll get from shopping around and finding the best specials.

When we recently looked at how the new flybuys isn't particularly good value, a few readers argued that it was unfair to claim that Coles would "aggressively bombard you with offers". Having received three emails from flybuys in the course of a week, I'd say that the marketing is well and truly on. What can you do about it?

Coles has revamped its flybuys loyalty scheme, changing the way you can earn points and redeem them. But the most important feature of the scheme remains the same: you will have to spend a massive amount of money to reap any long-term benefits, and you'll be sacrificing a lot of personal information to do so. We'll tell you how to make the most of flybuys if you do sign up, but you really need to examine whether it's worth it.

After a long absence, Telstra is rejoining the Flybuys loyalty scheme; since September last year, Optus has offered its customers the ability to earn Qantas frequent flyer points. Which telco offers a better deal in terms of loyalty points?

Coles' FlyBuys has recently joined Woolworths' Everyday Rewards in offering "activated rewards": deals which only apply if you click on a link to activate them and then spend a specified amount of money within a specified time frame. Lifehacker's advice on these remains unchanged: they're a good idea if they offer you a saving on something you actually needed to buy anyway, but not otherwise.