But some feel that the large sales figures may not mean anything.
Radio 1003's Mr Wong said: "S.H.E and Mayday endorse many products and it's quite likely that a portion of tickets for their concerts go to corporate clients and sponsors."
The girls of S.H.E are celebrity ambassadors of local lifestyle brand Osim, whereas Mayday lead vocalist Ashin has his own clothing label StayReal.
Both Unusual and Rock Records say corporate clients 'do make up a part of the ticket sales?, but both sides declined to reveal the exact percentages.
Mr Wong believes that ultimately, the real competition takes place on the day itself. True test
He said: "You can't just look at ticket sales, you have to see how many people turn up at the concerts.
"That will be the true test of the pulling power of these two groups of stars."
The real winners are Mandopop fans who love having more gigs here, even if it means having to decide which concert to go for.
Miss Wong Shuk Leng, a 22-year-old university student, picked Mayday even though she also enjoys S.H.E's catchy dance anthems.
"I like Mayday slightly better, so this time, I chose its concert over S.H.E's," she admitted.
"But, it'll be a great treat for us fans if there can be a collaboration between the two groups!"
Ms Ng Yanping, 37, who works in the education sector and never misses a Mayday show, is prepared for the crowds.
"We will most probably drive and get there very early," said Ms Ng, who will be catching the concert with her family.
"Park and ride looks to be an option too."
One ardent S.H.E fan, Mr C.L Lim, said that though the madding crowd is expected, he 'will still take the MRT' as it will be the most convenient.
"Most people will choose the MRT as they can just travel using the North-South, East-West and North-East lines easily from all areas."
WHAT: S.H.E Is The One World Tour Concert Singapore
WHERE: Singapore Indoor Stadium
WHEN: April 17, 8pm
TICKETS: Sold out
WHAT: Mayday DNA World Tour - 2010 Unlimited Edition
WHERE: National Stadium
WHEN: April 17, 7.30pm
TICKETS: $168, $138, $118, $88, $38 (students only).
Available from Sistic: 6348-5555
This article was first published in The New Paper.