So here it is – the social commerce acid test.  Are people willing to share their social graph data with big brands in order to get personalized offers tailored to their likes and activities?

We’re about to find out.

Amex has launched its Link-Like-Love social commerce program, a next-generation rewards program integrated with Facebook for Amex card holders and that offers personalized rewards based on Facebook Likes and check-ins.

Other players in the financial services industry – or any brands offering any kind of rewards program – take a look at Link-Like-Love; it could be the shape of things to come.

So if you’ve recently liked or checked-in to H&M, Lord & Taylor, Outback Steakhouse, Lenovo, Dunkin’ Donuts, 20th Century Fox, and Celebrity Cruises, expect Amex rewards from these brands in terms of personal discounts and offers.  Install the Link-Like-Love Facebook app and you get a personalized rewards dashboard.  No need to kill a tree and print out offers and coupons – simply use your Amex card.

So far, so smart – and Amex is thinking big – and beyond Groupon – with Link-Like-Love.  It is reaching out to local businesses, and offering to host and manage deals for businesses accepting Amex cards via its Go Social site (see video).  The Go Social area of the Amex site exudes the safety, security and gravitas of a mature financial institution – something that no amount of kooky Groupon copy can compete with.

For brands and retailers looking to pilot social commerce, Amex will be seen as a safe pair of professional hands.  Got it alone, go with Groupon, Google, Facebook – or Amex? The choice will be simple for many businesses – limited numbers of Amex card holders notwithstanding.

Amex’s Go Social looks like Groupon, Google Offers, Facebook Deals – done right.

We Like.

Even social commerce detractors – who are skeptical of the value of social technology in the context of retail – are bullish about the potential of the ‘portable social graph’ if it can allow brands to customize and personalize interaction with consumers.

If Amex can offer card holders compelling benefits through partner brands and businesses – Link-Like-Love could be the shape of things to come for member/customer rewards programs.

But here’s the but – amidst what we think is potentially best-of-breed social commerce brilliance.  To sign up for the personalized social rewards program, Amex card holders have to hand over to Amex not only information about what they’ve liked and where they’ve been, but also their basic information, profile information – and information about all their friends and what they like.  Basically their whole social graph.

[Update: July 22: American Express have been in touch and clarified that the social graph information is just used for the app – “Amex is not taking the social graph info, it’s only used for the app. We know the importance of privacy and we just want to make sure that our customers know that we do not keep that information, and it’s only used for the app”]

Whilst we think the nature of privacy is in flux, and that consumers will increasingly trade their information for relevance – the ‘request for permission’ screen when signing up for Link-Like-Love made us think twice – it’s scary, in an Orwellian kind of way.

The question is – will consumers go for it? Is the essential quid pro quo of social commerce – your data in return for relevance – a trade off that people are going to want to make?

Watch this space. The future of social commerce may be on the line.