Brands covet your attention, but there's something they want even more: your loyalty. And they're willing to offer you early access, special prices or free goods to get it.

Chances are you're already in at least one loyalty program: Americans have 3.8 billion loyalty memberships, according to a study from Colloquy.

But is it worth it to hand over your shopping profile to get the goods? And how do you know you're getting a deal?

How quickly do you get what you want?

The biggest reason people ditch loyalty programs, according to the loyalty study, is that it takes too long to earn rewards. Nearly 60% of respondents said they bailed on a program for that reason.

"A lot of people say, 'If it is going to take me more than three months, it's uninteresting to me,'" says Barry Kirk, vice president of loyalty for Maritz Motivation Solutions, a rewards company.

Some people enjoy the game of earning points and working toward a reward and are willing to spend more of their available attention on getting rewards, says Kirk. Others just want to reap the benefits that come from shopping for what they'd ordinarily be buying.

Either way, if it is too involved, go spend that attention somewhere else.

Kirk offers some modern benchmarks for rewards: you should look for programs where you earn 5% or more of what you've spent in points or rewards and you should reach a reward or benefit within 90 days.

What else (besides rewards) do you get from the loyalty program?

The company is tracking what and how you buy. That's how it sends you targeted appeals. If you're not comfortable with that level of intimacy with your retailers, get out now (and you should probably quit the internet, too).

"In exchange for the data you provide, you should receive a personalized experience," says Kirk. "If you're just being treated like everyone else, the rewards program probably isn't for you."

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Are you getting helpful texts or emails alerting you to deals on things you are interested in? Does the company come at you with information about deals or reward experiences that you find appealing? To make it worth your while, it should.

There are different kinds loyalty. Among them are what Kirk calls "cult" loyalty (you deeply identify with the philosophy of the company) and "mercenary" loyalty (you deeply dig the steep discounts).

If you're in it for the vibe, you're going to appreciate testimonials and personalized articles and videos that reaffirm your belief in the company. And If you're there for the deals, you're going to want to hear about those discounts early and often in very clear ways.

If you're not getting this kind of specialized communication, the program may not be the real deal for you.

How easy is it to track your progress?

Keeping track of your points and rewards should be simple.

The survey research shows that the biggest reason for participating in loyalty programs is that they're easy to use.

The best programs, said Kirk, are those that make it clear where you are in the awards process. "When you log in it tells you how close you are to achieving status, and how much more you have to go."

The accessibility of the program and how transparent the points are are things to look for.

If it takes too much time or is too difficult to track, you're probably not going to make the most of the offerings.

Are you earning rewards you want?

Younger people are more interested in experiences -- spa days, trips or activities -- over stuff, says Kirk. But experiential rewards are usually at higher levels. You'll need to decide whether you prefer to be rewarded more frequently or wait longer for a better payoff.

For some consumers nothing offers as much of an enticement as cash. Few loyalty programs run that way. But some financial programs, including the savings app Acorns, thank you for buying at certain companies with cash.

While that sounds good, you're going about it backwards to go reward shopping then signing up for a program so you can buy your way to the prize.

"Ultimately a consumer should start with brands you are already using," says Kirk. "Find out what do they offer for your loyalty."

Practice on the programs that offer smaller rewards at a faster turnaround time and learn to maximize your benefits, says Kirk. "From there, move on to the programs that take more spending and time, like airlines and hotels."