The internet offers a lot of legitimate free offers. Software developers give away first and beta versions as they continue to work on applications. Consumer products are given away to entice you to buy more once you taste, feel, see or otherwise try the product. Other goods are promotions, like Tshirts with a company logo.
It's frugally smart to take advanatage of those offers that you qualify for and that will benefit you. You might even find a few products that you really like.
BUT... there are other "free" offers you shouldn't touch with a ten foot pole, as the saying goes. These offers promise you $250 gift certificates or something similar, to well known stores, both online and off. You have to jump through many hoops, sign up for newsletters or other "free" (not) services or products or give your email address in many places.
Free, they are not. Besides doing all the work and clicking, you'll find the offer is entangled with so many strings attached that confusion either makes you quit altogether, or you begin clicking wildly just to get to the end of it all. Beware most of all, anything that requires a credit card number, bank account number or any other personal numbers or information.
Remember that anything that seems to be so easy to come by, usually isn't.