Free condoms and HIV tests! All you have to do is sign up for a drug that costs nearly $14,000 annually.

Call me skeptical, but I don't think many people are actually going to take Gilead Sciences (Nasdaq: GILD) up on its offer.

The biotech gained Food and Drug Administration approval to market its HIV drug treatment Truvada as a prophylactic to prevent HIV infection yesterday. As part of the approval, the company is offering the condoms to increase the effectiveness of Truvada as a prevention. The HIV tests are because patients infected while taking Truvada might develop resistance, which could make the virus harder to treat.

There are some patients that are appropriate candidates for Truvada as a prophylactic: people with partners that are HIV positive, for instance. There are a lot of people with minimal risk factors where the drug is not appropriate given the side effects and cost.

And then there's the group in the middle that are the key to gaining any meaningful increase in sales of Truvada: the patients that are engaging in risky behavior and could use an added layer of protection.

Of course, those patients could have a greater impact on their likelihood of infection simply by eliminating the risky behavior. And part of the Risk Evaluation and Mitigation Strategy program that goes along with the approval involves counseling patients on minimizing their risky behavior to further reduce the risk of contracting the disease (thus the aforementioned free condoms).

Ironically, people that are vigilant on the program and reduce their risky behavior probably don't need to take the drug.

The question: How many will really be that vigilant if they weren't willing to make the changes before? I just don't think Pfizer (NYSE: PFE), GlaxoSmithKline (NYSE: GSK), Merck (NYSE: MRK), Johnson & Johnson (NYSE: JNJ), and the rest of the companies that sell HIV treatments have anything to worry about. The approval of Truvada to prevent HIV infection isn't likely to prevent that many infections in the big scheme of things.