Why do you recommend using free weights on your weight gain website musclegaintips.com? Are they really necessary to build muscle? If so, why do gyms have more machines instead of free weights?
Free weights are absolutely necessary, and in my opinion a requirement for muscle building. Machines are excellent for isolation exercises and in some cases allow you to do movements that you cannot do with free weights, but overall, free weights lifts should be the main focus of any weight training program.
They allow the stimulation of certain supporting muscle groups when training. Stimulating these stabilizer and synergistic muscles will allow you go get stronger, and ultimately build more muscle faster. Yes, some can most likely still build large amounts of muscle using machines, but why make it more difficult if you already have a difficult time gaining weight?
I can speculate that gyms have fewer free weights and more machines mainly due to ignorance. Many people have been told that free weights are dangerous, or that they will make you too bulky or that machines are better because they are easier to do and safer. All of which are false.