How do students learn new skills or abilities? They typically watch someone else do it, like a teacher or through an instructional video, and then they try to emulate it themselves. This is true for changing a tire, as much as it is true for learning how to use a jigsaw.

How do good writers become great authors? They read the works of those who came before them, copying the parts that they find useful before going on to develop their own style.

If every researcher had to start completely from scratch, rather than standing on the shoulders of giants, scientific progress would effectively come to a halt as they would have no understanding of fundamental principles.

Affiliate marketing is no different.

There’s no reason why you need to work alone in a vacuum, devoid of the knowledge and experience of all the other Internet marketers all around the world. While it’s still true that successful affiliate marketing requires an endless cycle of trial-and-error, testing and retesting, you don’t have to reinvent the wheel when you could have access to the boundless data generated by other marketers and online users.

This data is useful both on an individual basis and as an aggregate, providing key insights into how your campaigns can be more successful. And this is where affiliate spy tools come into the picture. Part of the challenge is figuring out which tools to use, how to use them, and under what circumstances to use them. While the following list is certainly far from exhaustive, it should give you a good idea of some of the best tools that are available out there.

SEMrush

One of the largest and most robust tools you can have in your online arsenal is SEMrush because it’s so much more than just a single tool. While the site and domain audit features might be useful for blogs and other similar types of websites, the keyword analytics are going to be particular interest for affiliate marketers. The tool lets you spy on what your competitors are targeting, both in terms of search engine optimization (SEO) and search engine marketing (SEM), as well as for pay-per-click (PPC) campaigns.

This arms you with invaluable data so you can make more educated decisions about which keyword or keyword groups on which to focus your efforts. What’s great is that you can not only key in on the best keywords that your competition is using, but also what ad copy they’re using, the size of their ad budget, and where you’ll find the most/least competition. There’s even a magic tool to help you uncover more keyword ideas.

From the SEMrush homepage, you can preview what you’ll get when you pay for an actual account. When you search for a domain, for instance, you are provided with a dashboard of information about organic search volume, paid search traffic, total number of backlinks, top organic keywords, main organic competitors, top paid keywords and so forth.

After the 14-day free trial, prices start at $99.95 a month for the Pro plan.

WhatRunsWhere

The online advertising landscape continues to change and evolve over time, so it is positively critical as an affiliate marketer that you stay on top of the latest trends. Two such trends are the continued pushed toward mobile-optimized content and the ongoing rise of native advertising. Desktop ads are still the biggest player overall, but they are hardly the only piece of the pie you should be looking at.

Offering intelligent technology to spy on ad campaigns across all three categories is WhatRunsWhere. As with other advertising intelligence spy tools, the objective with this one is to help you stop wasting money by more effectively figuring out what is already working for the competition. In the case of mobile advertising, for example, you gain insight into where your competitors are placing their ads, who they’re buying from, and what ads they’re using. The database currently covers 90,000+ mobile websites across 7 different countries.

Native advertising is much the same. This is one of the avenues where you can buy some really cheap traffic, but you want to know exactly what publishers are actually serving up traffic that converts. WhatRunsWhere lets you see the top-converting creatives so you can design more optimized ads of your own.

You can get started with a $1 trial. After that, the pro package for both mobile and desktop intelligence is $399/month.

AdPlexity

Like WhatRunsWhere, AdPlexity also approaches desktop, mobile and native advertising. The interface is simple and easy to understand, making AdPlexity more approach for novices and users who are otherwise new to affiliate spy tools. Competitor campaign data comes from over 75 countries around the world, looking at everything from popup traffic sources to landing pages.

Mobile is huge here, because AdPlexity not only has the ability to scour mobile websites for valuable data about carriers, keywords, advertisers, affiliate networks and more, but it can also analyze the ads that appear on thousands of mobile apps. This is a serious source of traffic for a lot of marketers and one that should not be overlooked. Filter the results so that you’re only looking at campaigns being pushed to affiliate networks. This way, you skip branding campaigns that aren’t really relevant to your purposes. And then you can even rip the landing pages directly from your competitors too.

If you’re working in the adult vertical, then you might want to look into the more targeted AdPlexity Adult. The tool itself is fundamentally the same, except it is geared and optimized specifically for this niche.

Pricing is set at an all-inclusive flat monthly rate of $199.

KeywordSpy

One of the biggest appeals that KeywordSpy has to offer over the other tools on this list is that you really can use it for free without spending any money. There are paid plans where you wish to have access to richer data, particularly in terms of tracking keywords and performance over time, but the free search on KeywordSpy can offer a great place to start.

There are a few ways you can go about approaching this. You can search based on domain, keyword, destination URL or ad copy. When you do the domain search for SEMrush.com, for instance, you’ll immediately learn how much is the daily ad budget, what is the average cost per click, what are the keywords (and their position), and what are the top competitors (and how many keywords are they targeting). Below that, you can look into ad variations too, making it incredibly easy for you to clone their most effective PPC campaigns.

To unlock more data, like daily database updates and an invaluable ROI indicator, you will need to sign up for a paid plan. Either Research or Tracking on their own are $89.95 monthly, while the combination of the two is $139.95 a month.

Spy tools have become a practical necessity with affiliate marketing in 2017. If you’re not already spying on the competition, you’re going into this game with a serious handicap.