North has 26,625 members, the lowest total of the 10 Victorian clubs and well behind the 27,746 it recorded by this time last year.
However in 2009, the club played eight of its 11 home games in the first 11 rounds, meaning supporters had greater urgency to secure membership well before the AFL cut-off date of June 30.
Part of that stretch included five straight home games from rounds three to seven.
North has a similar run this year - four home games in five rounds - but that doesn't start until round eight.
By the midway point of this season, it still has five home games to play.
But Arocca conceded that members who were yet to re-sign were hurting the club by delaying their decision.
"I'm still optimistic that we'll get to 30,000 people. Every year throws up different spins," he said.
"I do like the idea that people have a greater sense of urgency about their footy club (as in 2009), because it does affect the way in which you plan for the rest of the year when you're not able to bank a solid core of members before round one.
"It is a sense of frustration because there is an element of uncertainty when members haven't signed up. What happens is you give it another week ... you get to round six, and then you start to say, 'Well, is it now worth financially joining if I'm only going to go to five home games?'
"You might be a cheerer of a club, an observer of a club or a fan of the club, but to use the word 'support' in modern football, is really all about membership."
North has budgeted for a strong six-figure profit in 2010, though Arocca warned that every 1000 members below 30,000 would wipe between $70,000 and $100,000 from the club's balance sheet.
In passing the 30,000 mark in 2008 and 2009, including its best-ever total of 34,342, North announced successive operating profits of $1,088,941 and $60,444.
Its 2008 membership campaign was largely driven by a recommitment to Melbourne after rejecting the League's offer to relocate to the Gold Coast.
But, with fan development central to its business plan, Arocca said the club was still making up for a nomadic existence which saw it play home games in Sydney, Canberra and the Gold Coast from 1999 to 2008.
"Our AFL-endorsed community zone stops about 500 metres from Arden Street. A symptom of a club having been a Trojan horse of the AFL interstate is that we lost our traditional supporter base," he said.
"We've got to get people back as members, we've got to get people as regular supporters and we've got to get people excited about the way which we play footy and excited about our future," he added.
Meanwhile, Arocca confirmed his own commitment to North and that he wanted to stay in his role for as long as possible.
A recent media report had linked him to a Sydney-based A-League franchise.
"I'm very settled, I love the place with a passion, I'm a passionate sort of person and if the media stories about me being approached by other codes or other organisations were correct, the answer would have been a very quick 'no'," he said.
