Social media can be good for getting people to buy products – and for getting them not to buy too.

Coming as it did the day after the governor of the Reserve Bank, Philip Lowe, told an audience of economists that average earnings for Australian workers were growing at the lowest level since the 1960s, the win by the AMWU against the company behind Streets ice-creams this week was a good advertisement for being a member of a union.

In his speech, Lowe noted that one of the reasons behind the 50-year-low wages growth was that there had been “an increase in the proportion of new employees hired on lower salaries than their predecessors”. What is also happening is that companies are using (previously) exceptional bargaining tactics to try to get current workers on lower salaries.

However, in an age of social media, when the dispute involves companies where brand management is vital, unions are able to fight back.

In August, when Unilever sought to terminate its enterprise bargaining agreement at the Streets ice-cream factory in Sydney, the AMWU quickly moved into action to organise a boycott.

Coming off the back of its recent successful boycott of CUB products, after 55 workers were sacked at its Abbotsford plant last year, it shows that unions certainly have learned how to use social media to their advantage.

The problem with organising a boycott of a company mostly involves alerting people of the boycott and then encouraging action. Whereas once this would have required expensive national media advertisements, now with Facebook and Twitter unions are able to get their message in front of people and in a way that encourages action.

The AWMU social media team has been particularly adept. When, for example the member for Mackeller, Jason Falinski, posted a gif of himself eating a Streets ice-cream to show support for the company, the AMWU twitter account absolutely roasted him and his rather inept method of eating it.

Of course the standard line is that Twitter activism is weak and good for getting likes and retweets but not so much for action. Similarly, the suggestion is that Facebook campaigns are great for getting people to share a video or picture but not for taking action.

But while this certainly does occur, and you should never fall into the trap of assuming what you observe on your social media is a true reflection of voters or national opinion, where it is effective in campaigns is against the very thing that companies so love about social media.

The reason Facebook is one of the world’s biggest companies is not because we all like sharing pics of our cats but that companies love using it for advertising while we share our cat pics.

But while social media can be good for getting people to buy products, it is likewise very good for getting people not to buy them as well.

The AWMU team, for example, used its Facebook page to disrupt the social media launch of the Streets Gaytime Sanga – and that resulted in the launch video being removed after people inundated it with negative comments.

In the end the boycott clearly was having an impact – and it probably is not a coincidence that Unilever agreed to a deal that saw the end of the boycott the day before the first Ashes Test began. The last thing any ice-cream company needs is people avoiding eating its products during summer.

But while this boycott worked, and is a good example of the power of a union, the broader problem is that the tactics employed by Unilever are becoming more common and will not always be used by companies with such consumer-driven businesses.

As is the case with social media campaigns in the US supporting or boycotting companies for their political positions, or the actions taken by companies in light of recent accusations of sexual harassment – which would once have involved much sweeping under the rug – the voice of social media is loud and forces companies to act.

But it is easier to organise a boycott of a product people buy at the supermarket than it is when that item might be just part of a production chain, or is a university – such as Murdoch University which earlier this year successfullyapplied to the Fair Work Commission for the right to cancel the EBA with its staff.

And the issue is that cancelling enterprise bargaining agreements, in effect blackmailing workers into accepting a new agreement, is becoming a more common option.

The old ways of renegotiating, using the expiring agreement as the starting point, is being replaced by this so-called “nuclear option” .

The Department of Employment, in its submission to the Senate committee inquiry into Corporate Avoidance of the Fair Work Act, noted that of the 847 EBAs that had been terminated from 2014 though to September 2016, nearly 60% had occurred in the last 12 months of that three-year period.

In the past 12 months there were as few private sector EBAs approved as occurred in 1997 – a time when there were nearly three million fewer people employed than now.

Employers are doing what they can to get their workers off EBAs and their generally better union-negotiated conditions and wage rises.

The ALP-led Senate committee recommended that the Fair Work Act be amended such that the Fair Work Commission would be prevented from “terminating an agreement where workers would be worse off as a result of the termination” – and this remains the ALP’s policy.

The victory for workers in the Streets case is a prime example of how unions can achieve results. But it is also a visible insight into wage negotiation tactics. And while the boycott might make other more retail-dependent companies wary of going the nuclear option, while the law allows it, many more companies under the radar will continue to do so.