"I would expect ticket sales for the three shows would gross in the region of about $25m," the source said. "It is possible Adele would get about $18m from that once overheads are paid.
"These days it is not unusual for artists to get about seventy five percent or more of the net ticket sales.
"I expect Adele will take home more money from her New Zealand gigs than other big live acts like the Rolling Stones, Robbie Williams and AC/DC have done in the past when they have toured here."
It is believed another $2m could be heading Adele's way from merchandising sales at the gigs.
"Adele has struck it lucky as there are some big concerts happening in New Zealand this year and next by the likes of Bruce Springsteen, Guns N' Roses and Coldplay, which tend to attract a baby boomer audience," the source said. "Adele also attracts older music fans but she appeals to a younger crowd too."
Tickets being put on sale in the run up to Christmas would also have helped boost the numbers, the source added.
"Some people would have bought tickets as Christmas presents, so all up it has been a case of Adele being exactly in the right place at the right time."
• Adele will perform on March 23, 25 and 26 at Auckland's Mt Smart Stadium.