Drug samples are often offered to physicians by pharmaceutical companies, either by a pharmaceutical rep in person or via sign up online or mail in form. The cheapest new drug starts at about $150 per month, with more of them being over $200 per month. The combination inhalers may go for $350 per month. So how free do the samples look if they set you up for a high monthly expense. "But I have great insurance which will pay for the drug" you might add.
Your insurance generally won't let you have access to the new drug unless they know you've taken a generic drug and the "covered" brand names first with documented failure or intolerable side effects. Then your physician must submit a document to the insurance company stating your side effects or reactions to the medication. THEN they may cover the medication.
So, watch out for samples. Nothing is free.