"That was particularly in the economics area and also in our communications and political strategy in relation to raising our co-leaders' profiles."
The most visible evidence of the Greens' quest for economic credibility was in co-leader Russel Norman's preference for a conservative suit and tie. However, that was backed up with a willingness to discuss or debate the detail of economic issues and policies.
His co-leader Metiria Turei consolidated her profile and status as a contributor to debates on social justice issues with moves including a well received speech to the House on child poverty which, while deeply personal, was written with input from professional contributors.
In terms of the campaign proper, Mr Campbell says the style was closer to that of the major parties than it had been in the past.
"I guess it was a recognition that election campaigns are becoming more and more presidential and while we're not in that game in terms of Labour and National it is important that there are co-leaders or leaders that the public have trust and confidence in and know who they are."
Ms Salole said the party had built on its success in 2008, employing the same "winning formula" but "getting sharper and more sophisticated in delivery and more ambitious with our goals".
That saw greater discipline about having priorities - "Jobs, Rivers, Kids".
"That was an extraordinary wedge for us. It helped us penetrate into a very crowded campaign space and we hadn't been able to do that in the past, possibly because we hadn't been as consistent in saying what we were doing."
Those priorities were also successful because they had broad appeal, "no matter where you are on the political spectrum".
While the Greens have in the past been good at wringing every single dollar and ounce of energy out of its 4000 or so members, one of its successes this time around was the development of the "Green Machine" as a way of engaging and harnessing supporters who weren't ready to become members but wanted to do more.
Ms Salole said the "tremendously successful" strategy mobilised thousands of "slacktivists", mostly younger people who were passionate about the environment or securing change but who were otherwise more likely to rant about it online rather than stuffing leaflets in letter boxes.
While some did end up helping out with leaflet drops, they made a major contribution by helping maintain a significant online presence for the Greens thereby facilitating wider direct communication with voters.
The Greens also had help from a more activist volunteer in the shape of actress Robin Malcolm, whose attack on Prime Minister John Key landed her and the party on the front page of the Herald.
"It certainly raised the profile of our campaign launch", said Mr Campbell.
Finally, Ms Salole said the Greens campaign, in which the party's policy gains under its memorandum of understanding with National in the last term, was successful in that it communicated the party's independence while still getting the message across that it could make progress on its policies no matter who got into Government, "not if we got into Government".
"A Green vote wasn't a wasted vote in that regard."