Dr Lee said tourists from America and Australia probably wouldn't base their travel decisions on what had happened with the dairy giant.
"Asian countries on the other hand, particularly China, may view the same ad with a bit more scepticism."
Tourism New Zealand is trying to promote the country as a destination where visitors can indulge in food and wine or luxury experiences.
Its research shows that walking, cycling, golf, fishing and skiing appealed as activities for overseas visitors, particularly Australians.
Tourism NZ's general manager for communications and marketing, Justin Watson, said promoting NZ as Middle Earth had had a noticeable effect on the way visitors viewed New Zealand as a destination.
The campaign was running because the key advertising period in overseas markets was from August to December.
He said Fonterra's issues had affected the way people viewed New Zealand as a tourism destination "so the campaign should help to try to rebuild some of that".
Its research showed 73 per cent of people surveyed showed their interest in visiting New Zealand increased after seeing the previous campaign.
The international visitor survey, showed 8.5 per cent of visitors in the first quarter of this year and 8.4 per cent in quarter two said The Hobbit influenced their decision to visit.
Survey
100 per cent Pure Middle-earth
73 per cent of people surveyed said their interest in visiting New Zealand increased after seeing the previous 100 per cent Middle-earth, 100 per cent Pure campaign.
8.5 per cent of all visitors in the first quarter of 2013 and 8.4 per cent in the second quarter said The Hobbit had influenced their decision to come here.
Figures: Tourism New Zealand