Council bosses are hopeful that the First Light Festival can return to Lowestoft next year, and have agreed to put up to £200,000 into organising its return.
The first festival was held on Lowestoft's south beach during June's midsummer solstice, with the council committing £120,000 to the event for three years.
Data for the first festival revealed around 30,000 people attended the event - three times more than the anticipated 10,000, and generated up to £900,000 in economic benefits.
On Tuesday, East Suffolk Council's cabinet agreed to contribute up to £200,000 from business rates to support its return in June 2020, subject to other funding streams being approved.
Conservative cabinet member for economic development, Craig Rivett, said: "We all need to be ambassadors for Lowestoft and sing its praises.
"Thirty thousand visitors attended the event and up to £900,000 went into the local economy.
"With this additional support we will start to expand the number of visitors attending and strengthen Lowestoft's position as a venue for contemporary arts and venues."
Mr Rivett said there were plans to increase the space available, and explore profit sharing with some of the commercial stallholders for 2020.
The 24-hour event featured live music, dance, science demonstrations, film screenings, talks, wellbeing sessions and children's activities, and gained media coverage on The One Show and BBC Radio 6 Music.
The event came out of the Seafront Vision Strategy approved by Waveney District Council in 2017, which sought to increase visitor numbers to the seaside town with the potential for tourism income to triple.
Additional data suggested that every hotel and B&B room was booked, with more than a third of those attending not having visited Lowestoft before.
According to the cabinet report, 96% of those outside of Lowestoft who visited would return.
Work organising next summer's event is underway, but it is understood to be dependent on securing additional funding from other sources.
If the same return on investment is seen next year, the town will benefit by around £2million economically, the cabinet report claims.
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