When someone begins internet marketing, their first question may be along the lines of 'is affiliate marketing legal?' Very fair point, and, and this is something that everyone seems to be asking. Because a lot of affiliate/internet marketing seems often too good to be true, then, it's a very fair question to ask. The fact is, like everything there is a degree of illegal activity which goes on in the world of internet marketing. Is affiliate marketing legal will often result in practices which are honest, and not honest.
If you are going to be promoting a product via blogs, articles and other legit methods of sticking your products in the faces of others, then you're going to be totally OK. However, if you begin spamming, adding hidden charges to people, then you are going to be breaking the law.
If you are going to use email marketing, then make sure that you always ask permission before you send emails, and always provide an unsubscribe link at the bottom of your emails. Thankfully, this isn't hard to do with automatic services like Aweber. And if someone asks you to stop, then stop! Continuing to send emails turns you into a spammer, this this is where the affiliate marketing legal people will pounce down on you for violating spamming laws.
The thing is, internet marketing is actually very legal, and many people are very happy that it exists. For example, if affiliate marketing was make illegal, then Google would go bust overnight. Fortune 500 companies would fall down, and the world would stop turning. You see, affiliates are everywhere, and the affiliate marketing legal team won't pull down the practice any time soon.
Is affiliate marketing legal? Well, it is. As with everything, there are black hat and white hat ways to do it all, and the black ones are frowned upon. A black hat method may involve link spamming, dominating search engine results. The affiliate marketing legal people won't consider it breaking the law, but Google and the others will hate you for messing up their results, and blacklist you. Black hat methods are for those who live by the 'live fast' rule. Earn a lot of money very quickly, and disappear very quickly.
It is a far better use of your time to employ white hat methods such as content marketing, natural search engine optimization techniques like backlinking, in other words building a business over time. This method is more likely to be better for you too, since you'll earn more over time, instead of make a buck quick as possible.
Is affiliate marketing legal? Well, as far as I can tell, it is. Many affiliate I know have never had trouble with the law, and once you've done your research, you'll know what the law expects and how to stay within it's boundaries. Oh, and my advice to you is to stick to white hat methods. They'll be far better for you and your income in the long run.