Back on June 13, I wrote about DexCom Corp. (NASDAQ: DXCM) as one of the top 25 stocks for the NEXT 25 years. The stock was just under $7 with a market capitalization of $180 million. Today the stock is at $9.61 with a market cap of $280 million. The shares have performed well these past two and half months, but the best is certainly yet to come.

DexCom is targeting the massive diabetic market of five million Americans who suffer from this disease. These patients need to monitor their blood glucose on a daily basis and treat it with injections of insulin.The methodology used by most patients is a painful pin-prick usually on a finger. The problem -- therefore the opportunity for DexCom -- is that the daily readings can be scattered and inconsistent. The readings depend on time of day and recent dietary intake. With DexCom, however, the reading is continuous and fluid during the course of a day, thus allowing the patient to self-administer insulin at the right moments. Plus, with DexCom, there is no painful pin-prick.

The NEXT company in my on-going series of the top 25 stocks for the NEXT 25 years is DexCom, Inc (NASDAQ: DXCM). This San Diego, California-based company has the opportunity to address the millions of people that suffer from diabetes. DexCom manufactures a continuous glucose monitoring system, which is extremely user-friendly and helps improve the diabetics' quality of life.

DexCom's business model is the classic razor-razor blade. DexCom sells a wireless glucose monitoring device, for about $800 per unit. Because of the wireless component, the monitor is completely mobile with the patient and can even be hooked to a belt like a cell phone. The company also sells the "implantable" disposable sensors that the patients slip-in just under the skin. Each sensor is good for up to 72 hours. The sensors come in a five-pack and sell for about $175 a pack.

Patients no longer have to endure the painful finger prick to draw a minor amount of blood to detect their glucose level. Also, with the monitor and sensors, the readings are far more accurate and continuous so the patient can administer the necessary insulin at the precise time versus a bit of a guessing game.