The easiest way to top up your points and miles without spending a dime

"You need more points to purchase this flight," read my Southwest app when I was recently trying to book a weekend getaway to Florida. It turns out I was only 50 Rapid Rewards points short of booking a flight that would've cost upwards of $400 roundtrip in cash.

So close! Otherwise, the trip was perfectly planned, and I was about to cancel it over a flight I was only a few points away from being able to book for free.

But I found a solution: Surveys. I signed up for Southwest's Rewards for Opinions, and after taking two surveys, I earned enough Rapid Rewards points to save my trip.

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Southwest isn't the only airline that lets you do this: various other major airlines and hotel chains let you do these types of surveys, so you likely can get points and miles for your preferred loyalty program through surveys.

Let's dive in and investigate more about surveys for points and miles.

Overview

Here's how surveys for points and miles work: companies ask your thoughts on various subjects, and you get rewarded a fixed amount of points or miles after each survey.

Once you complete a survey, your answers then get pooled with the answers of others, and as a result, businesses are able to see the general attitudes of people toward their products and policies.

Surveys for points and miles can be about anything: I have taken surveys on topics ranging from cars to electronics to delivery services. Each survey generally takes 10 to 30 minutes to complete, which doesn't seem long — but this time can easily add up.

Here are some of the major airlines and hotel chains that offer surveys with the links to their respective survey websites:

• Alaska Airlines: The Opinion Terminal
• American Airlines: Miles for Opinions
• Hawaiian Airlines: Opinions Take Flight
• Hilton: Guest Opinion Rewards
• JetBlue: Points for Surveys
• Southwest Airlines: Rewards for Opinions
• Spirit Airlines: Points for Thoughts
• United Airlines: Opinion Miles Club
• Wyndham: Opinion Rewards Panel

Notably, Delta Air Lines does not offer surveys for miles.

Many companies on this list also have partnerships with e-Rewards -- another survey site that allows you to transfer points and miles to various partners.

And chances are, you likely have some points or miles for at least one of the airline or hotel programs above. Surveys could help you turn those points or miles into a reward booking. Although each survey takes some time to complete, the time investment could be worth it in certain situations.

When are surveys for points and miles worth the time?

Here are three situations where surveys have proven to be especially helpful:

When you need a small sum of miles. I have personally found surveys quite useful when I am a few miles short of an award ticket, such as in my earlier Southwest example.

Another example is when I was booking a United flight from Savannah, Georgia (SAV), to Chicago O'Hare (ORD) earlier this year. The award ticket cost 5,500 miles — but I only had about 5,200 miles.

Again, I was initially deflated that I was so close to an award ticket but couldn't book it — after all, I'm a college student on a tight budget who would love to avoid spending money on a plane ticket. I don't own a United credit card and was not planning to earn miles before booking, so there were seemingly no other ways to get the 300 miles I needed for the award.

But then I remembered that I could take a survey or two to reach my mileage goal, so I signed up for Opinion Miles Club. It was my first time taking a survey for United miles, so in addition to earning 50 miles for completing a survey, I also earned a 300-mile sign-up bonus. This one survey alone with the sign-up bonus gave me enough miles to book the flight, so I avoided having to pay for a revenue ticket.

When miles are about to expire. Each time miles from surveys are posted to your account, they prevent your existing miles from expiring. This makes surveys a great non-credit card option to keep your existing points and miles — and to earn a few more, too. Surveys are especially helpful if you have thousands of miles that you don't want to expire but don't have any near-term travel plans or the proper credit card.

Related: How to keep your points and miles from expiring

To take advantage of a sign-up bonus. Taking a survey to receive the sign-up bonus could be worth it, especially if you're a few hundred points or miles away from an award booking.

Keep an eye out for promotions: Hilton recently offered 10,000 HHonors points as a sign-up bonus for completing your first survey, but this deal has since been dramatically lowered to 1,250 HHonors points.

Here is a list of the current sign-up bonuses offered for various airline and hotel loyalty programs:

• Alaska Airlines: 400 Mileage Plan miles
• American Airlines: 250 bonus AAdvantage miles
• Hawaiian Airlines: 350 bonus HawaiianMiles
• Hilton: 1,250 bonus HHonors points
• JetBlue: 400 bonus TrueBlue miles
• Southwest Airlines: 500 bonus Rapid Rewards points through Rewards for Opinions
• Spirit Airlines: 400 Free Spirit points
• United Airlines: 300 MileagePlus miles
• Wyndham: 500 Wyndham Rewards points

Should you spend your free time taking surveys for points and miles?

A common perception is that taking surveys for points and miles for long periods of time is not worth doing because of low mileage accrual after long surveys — but is this really the case?

To give that a closer look, I took surveys for two hours with The Opinion Terminal — Alaska's survey partner — to see how many Mileage Plan miles I would receive. I chose the shortest surveys with the highest payouts to maximize my gains.

I ended up earning 391 Mileage Plan miles in the two hours of taking surveys — or 195.5 miles per hour. Based on TPG's latest valuations of the Mileage Plan program, this is a mere $3.52 per hour worth of Alaska miles.

This was my first time doing a survey for Alaska, so I also received a 400-mile sign-up bonus — worth about $7.20. However, my total earnings, including the sign-up bonus, were still only 791 miles — or $14.24 worth of Mileage Plan miles — in the two hours of survey-taking.

To get enough miles for the cheapest award ticket on Alaska, which costs 5,000 miles, I would have to spend about another 17 hours doing surveys at the rate I was going — something I'm not willing to do.

As you can see, it is likely not worth it to take these surveys for long periods of time. However, if you enjoy taking surveys or are only a few hundred points or miles away from an award, these surveys can be a great way for you to inch closer to your next award booking.

Things to consider when completing surveys for points and miles

Points and miles from surveys might not post instantly. Although I frequently receive points and miles almost immediately after finishing a survey, the fine print says that it could take up to six weeks for miles to post.

For my Alaska Airlines example, the miles were posted almost instantly to my Mileage Plan account after completing each survey; however, when I took my first Hilton survey, the HHonors points didn't post for a few weeks.

You will be bombarded with emails. I receive one to two emails per day from Opinion Miles Club alone offering me to take surveys; these frequent emails can be bothersome. And if you unsubscribe from the emails, your account will be deactivated.

One workaround to the frequent emails is that you can automatically send the survey emails to a certain inbox that is separate from your main inbox. You could also give a secondary email when signing up on the survey website.

You might not qualify for every survey. When I was taking surveys for my Alaska Airlines example, I was excited at an offer to take a 20-minute survey for 733 Mileage Plan miles — worth more than $13.

However, as soon as I began the survey, it abruptly ended. It turns out I was not eligible to complete the survey. As a result, my 733 miles turned into a mere five miles — the sum given by The Opinion Terminal when you are deemed ineligible for a survey you already started.

So, take note that you will not always qualify for every survey — and that can be a letdown when the mileage yield is high.

Bottom line

Although spending long periods of time taking these surveys is not always worth it, they can be a great supplemental tool in earning enough miles for your next award trip — especially if you are only a few miles away from an award.

Editor’s note: This post has been updated with additional information about airlines that offer surveys.