Soon you could be competing with a robot for a job.

Economists are sharply divided over the exact timing of the threat from robots and other forms of futuristic technology. Some see an imminent threat, others believe it won't happen until later this century -- if at all.

Yet Amy Webb, a digital media futurist and founder of Webbmedia Group, predicts at least eight career fields are "ripe for disruption" very soon -- like in the next 10 to 20 years.

"You should be quite worried," Webb said at the Milken Global Conference in Los Angeles last month. She points to these eight careers, in particular:

1) Toll booth operators and cashiers: People who work in the transactional space shouldn't be big fans of the Apple Watch or Apple Pay.

That's because the rise of wearable technology and mobile payment systems may make jobs like toll booth operator and grocery store cashier virtually obsolete.

"There is no real need for a person to be there every step of the way," Webb said.

2) Marketers: Powerful advertising tools of the future may allow brands to fashion their messages to customers with precision accuracy.

Webb pointed to new experiments with technologies that study customer behavior to identify what kind of ads will be most effective.

"This is pretty much unlike anything we've seen before," she said.

If these tools work, they may translate to smaller creative and strategic teams at marketing and ad firms.