Social networks are poised to become even more personal as they become a vehicle for e-commerce, too, predicts the co-founder of a payment processing startup.

DUBLIN, Ireland -- Today, you're likely to use dedicated Web sites or apps to buy books, apps and taxi rides. Tomorrow, that e-commerce will take place on social network companies like Facebook and Twitter, too.

That was the prediction of John Collison, co-founder and president of payments processing startup Stripe, speaking Tuesday at the Web Summit tech conference here.

Why? Because people spend so much time on social networks, it's inevitable merchants will want a presence there, Collison said. Anything to lower the hassle of online payments -- which by the way is Stripe's core business -- will be in high demand.

People browsing Twitter or Facebook who see something they like today must click through to a website and plod through five or six steps to make a transaction, he said. "More people will do this if you make it easier," Collison said. "Given that people are spending so much time on [social network] platforms, it's natural to make it easy for merchants to sell."

E-commerce would be a significant expansion of the scope of social-networking businesses. Typically they are funded today by advertising that can lead only indirectly to sales, though Twitter has experimented with a "buy now" button. E-commerce on social networks also could help drive revenue on mobile devices -- an area in which it's been harder to make money from ads.

It's a potentially huge business. Analyst firm Emarketer estimates that in 2014, businesses worldwide sell consumers $1.47 trillion worth of goods and services, a 20 percent increase in e-commerce over 2013.

Facebook already knows your closest family and friends, your hobbies and interests, your politics and physical location, so you might be leery of giving it your credit card number, too. Using Stripe, though, lets them offer payment transactions without holding onto that data themselves. Stripe has partnerships with both Facebook and Twitter.

Collison's 175-employee San Francisco-based startup has a direct interest that kind of expansion. The company makes money powering its clients' financial transactions, online and in apps. It's got prestigious partners, including Alibaba Group's Alipay system and more recently Apple Pay.

Though it got its start in Ireland, Stripe moved to San Francisco and is that classic Silicon Valley startup that embraces a role "disrupting" the business of incumbent powers -- in this case, banks. So what's going to disrupt Stripe?

Bitcoin, perhaps, Collison said. The electronic currency remains something of an unknown quantity.

Stripe has begun accommodating Bitcoin, he added, launching a service this year that lets merchants accept payments. "It's a way of addressing customers, especially internationally, who may not have been able to pay before," Collison said.

At a conference devoted to the European startup scene, he told the audience that it would be easier to launch a company in Ireland now, with more opportunities to raise money and hire programmers.

"The reason we moved to San Francisco was our potential customers were there, our potential employees were there," Collison said. "Silicon Valley has a very strong network effect."

That network effect now is coming to Ireland, though, he said.

Corrected at 6:04 am PT to reflect that in e-commerce transactions powered by Stripe, a social network doesn't need to know a buyer's credit card number.