Before I began thinking about Netflix (Nasdaq: NFLX) as an investment, the company was just a joyful experience for me -- its signature red envelope dropping through the mail slot once or twice a week as I happily made my way through my ever-growing online movie queue. In the course of writing about Netflix and its surging competition, however, my viewpoint has, sadly, shifted from romantically bullish to realistically bearish. Here's why.

It's a jungle out there
And the king of the jungle is Amazon.com (Nasdaq: AMZN). For the moment, and into the foreseeable future, Amazon is Netflix's biggest competitive threat. Amazon has its fingers into just about everything, giving it a significant market-space advantage. With trailing twelve months' gross revenue of just over $48 billion versus Netflix's $3.2 billion, Amazon can take its sweet old time developing its own fledgling movie service, Prime Instant Video; negotiating content deals from a position of relaxed confidence; and taking a more thoughtful, considered approach overall.

Alternatively, Netflix has its fingers in exactly one pie. Whether by wire or post, delivering media is the company's only way of generating revenue. It stands or falls based on how well that single channel of profit is doing. As such, it will need to scramble to keep up, which is never ideal.

Slow and crushingly steady wins the race
Amazon has taken full advantage of this revenue-diversity gap. Prime Instant Video is a feature of Amazon Prime, which, for $79 per year, gives members free two-day shipping on a vast number of physically deliverable items in the company's extensive inventory. They also get free access to Amazon's video-streaming catalog, which the company is slowly but surely building up to a competitive level of content.

Most recently, Amazon signed a licensing deal with Viacom, owner and operator of Nickelodeon, VH1, MTV, TV Land, Spike, Logo, BET, and Comedy Central. This deal will let Prime members choose from thousands of shows from these channels, in addition to the films and television shows already available from Warner Brothers, PBS, CBS, Disney-ABC, Fox, Sony, and NBC. The Viacom deal brings Amazon's grand total of instant-streaming titles to a formidable 15,000.

Don't mind us looking over your shoulder
But enough about Amazon, because there are even more sharks circling the lone swimmer Netflix -- sharks that, sooner or later, are going in for a bite. Apple (Nasdaq: AAPL), for instance, has this little thing called Apple TV, a box you connect to your television that lets you stream video through iTunes.

If you've never heard of Apple TV, join the club. The company has yet to put a major effort into developing and marketing the product. CEO Tim Cook even went so far as to recently quip: "Our Apple TV product is doing quite well … but in the scheme of things, we still classify Apple TV as a hobby." 

Apple's casual attitude is excellent news for Netflix, because as soon as Apple decides to take Apple TV beyond mere hobby-dom, Netflix will have another fiercely competitive threat on its hands, one with more than $127 billion in TTM revenue -- diversified across the wildly profitable iTunes and the most sought-after consumer-electronic devices in the world -- and close to $100 billion in the bank.

Apple doesn't necessarily invent the next big thing, but instead takes an already existing good idea, like video-streaming, and then does it market-crushingly better than anyone else.

I want my Google TV
Google (Nasdaq: GOOG) has its own version of Apple TV called, not surprisingly, Google TV. Like Apple, Google hasn't yet made Google TV a priority. But also like with Apple, when Google does decide to make it a priority, the company has the size, reach, and financial firepower to become a very serious threat to Netflix very quickly.

Not having all one's eggs in one basket counts. Look at Barnes & Noble (NYSE: BKS). The once-mighty bricks-and-mortar bookseller is slowly but surely losing its business to a greatly diversified competitor, (speak of the devil) Amazon. Had B&N been able to get beyond mere books and music in the same way Amazon did, it might not be trapped in the corner it is today. Netflix can relate, or rather, will be able to soon.

Don't despair just yet, Fools
The company, for now, is holding its own. It's not like Netflix doesn't get it, or isn't making the right moves -- I just don't think, given the existing competition and what is surely coming, the company will survive past the next few years, at least not on its own. In the meantime, I'm going to keep enjoying that beautiful red envelope -- and all it represents to me personally -- sliding through the mail slot, and keep dutifully paying my Netflix bill every month until I'm properly wooed away.

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