I tried Prime Now, Amazon's 2-hour delivery service - and I discovered a glaring flaw

• I tried Amazon Prime Now, the company's two-hour delivery service.
• I found it was full of surprising costs, and it took longer than two hours.
• Still, it's massively convenient for some specific needs.

Amazon Prime Now is getting all the attention these days.

The service, which promises two-hour delivery for a wide variety of items from grocery to electronics, has been expanding rapidly across the country.

Most recently, Amazon added Whole Foods to its list of Prime Now stores in four select cities, with plans to roll out to more cities throughout the year.

Prime Now is also one of the most important pillars in Amazon's quest to take a bigger bite of the grocery market by combining convenience with selection.

So, with Amazon funneling efforts into growing the service, I decided to check out how it really works: