Want to shop smarter online? You may want to check out your credit card’s Internet “shopping portal.”

It’s one of the fastest ways to rack up rewards points, and all you have to do is click a link to reap the benefits. Shopping portals typically offer bonuses that will double or triple the points you’d get from a traditional purchase. Some offers will give you more than 10 times the points.

Shopping portals emerged about a decade ago as a creative way for banks to strengthen their relationships with rewards-hungry consumers, says John Ulzheimer, president of consumer education at SmartCredit.com.

They’ve rapidly expanded since then, especially after the recession, as more consumers turned to their computers to make purchases, says Michael Misasi, an analyst with Mercator Advisory Group. Research firm eMarketer projects that consumers spent $224.2 billion shopping online in 2012, and that figure is expected to balloon to $361.9 billion by 2016.

Portals have become a popular middleman in the world of e-commerce; consumers go to the portal with an idea of what they want to buy. And the portal helps pick the right online store, says Brian Kelly, founder of ThePointsGuy.com.

Here’s how they work. First, log in to your credit card account. Then, look for the portal. You may have to do some digging, but somewhere on the page, you’ll see a link directing you to a website where you can earn additional rewards for shopping online. Once you click on the link, a cookie is stored on your computer, so that when you check out, you automatically receive bonus rewards.

The bonus rewards are just that — a bonus to what you would normally receive. You could get more cash than usual on your cash-back card. If your card gives rewards points, the portal will add even more points to your purchase.

If you’re looking for the retailer with the best bonus offer, Kelly suggests using sites such as evreward.com, which compile all of the top deals from thousands of online stores.

Both credit card companies and retailers stand to gain from shopping portals.

Banks gain valuable information on your shopping habits when you use their portals. They may use that information to send you targeted offers for items they think you might want. Misasi says this kind of targeted marketing has the potential to bring revenue to banks “in the hundreds of millions of dollars, maybe even billions of dollars” industrywide. Misasi estimates a single bank could get several million dollars annually from targeted offers and sales on shopping portals.

Retailers, meanwhile, have lined up to offer deals through shopping portals. They’ve been willing to pay hefty fees — some can go as high as 10 percent of the transaction value — to be placed on the portal. It’s worth it, Misasi says, because it gives retailers instant access to untapped pools of motivated consumers.

“That’s where the return on their investment comes,” Misasi says, “by generating lasting relationships with new customers.”

Most major credit card companies have shopping portals for cardholders with online access. Here’s how to find them and what to expect.

Credit card shopping portals

1. Discover
What to expect: You can earn up to 20 percent in cash back on purchases at ShopDiscover. The shopping portal features more than 200 retailers.
2. Chase
What to expect: Chase’s shopping portal is part of its Ultimate Rewards program. You can get cash back (starting at $20 for 2,000 points) on merchandise such as electronics, gift cards and travel with no blackout dates.
3. Citi
What to expect: Earn an average of 5 percent cash back at more than 400 online retailers at Citi Bonus Cash Center.
4. Bank of America
What to expect: Earn up to 20 percent off by shopping at retailers on the bank’s shopping portal, Add It Up.
5. Capital One
What to expect: Earn extra Capital One points by shopping at Perk Central, which offers more than 300 online merchants. Points can be redeemed for merchandise and travel, but not cash.