The Apple iPad poses a threat to both the e-Reader and portable gaming device markets, amongst others, according to a new study. Citing Resolve Market Research’s new iPad study, Mashable reports that when asked what products they would not buy after owning an iPad, 49% of users said an E-Reader, followed by 38% who said a portable gaming console. This was notably higher than the percentage of iPad users who said they wouldn’t purchase a netbook or laptop (32%) or an MP3 player (29%). Somewhat surprisingly, 37% of respondents who either owned or planned to buy an iPad said the device would be their first Apple product, a percentage eclipsed only by those who had owned an iPod (49%), and ahead of those who had owned an iPhone (24%) or MacBook (16%). Finally, while “early adopter” iPad owners tended to be in the 22-45 age group, the next group of adopters and those interested in buying the device were generally older than 45 years of age.