By almost any measure, internet entrepreneurs Janus Friis and Niklas Zennström achieved more business success by the age of 40 than most entrepreneurs could hope to achieve in a lifetime.

Friis, who is in his early 30s, and Zennström, who is now in his early 40s, were the founders of popular peer-to-peer filesharing service KaZaA.

Facing a copyright infringement lawsuit, the duo sold KaZaA to Australian firm Sharman Networks in January 2002 and even though the purchase price was only reportedly $1mn, Friis and Zennström had made a name for themselves.

They took peer-to-peer technology to the world of internet telephony and the company they founded – Skype – was sold to eBay for a whopping $2.6bn in 2005.

Young, rich and still eager to build, Friis and Zennström stuck to what they knew best – peer-to-peer technology – and set their eyes on the world of television.

They foundedThe Venice Project” in 2006 and raised $45mn from a who’s who of the investment and media worlds, including venture capitalists Sequoia Capital and Index Ventures, Hong Kong billionaire Li Ka-shing and media companies CBS and Viacom (although details on Viacom’s “investment” are sparse).

Unveiled as Joost, the goal of Friis and Zennström’s new startup was to distribute television and other professional video content using peer-to-peer technology. By downloading the Joost client, Joost users would have the ability to watch high-quality, ad-supported video content on their computers.

Today, Joost has deals with Viacom, Warner Music, Endemol, Freemantle Media and CBS, amongst others. Not too shabby.

But while Zennström claimed in July 2007 that Joost had signed up more than a million beta testers, Joost has seen competitors such as YouTube and Hulu dominate the spotlight.

Earlier this month, it was revealed that Joost is planning to ditch the Joost client and will be offering a web-based player more similar in nature to the web-based players YouTube and Hulu offer.

The reason? It became clear that consumers are less-eager to download and use a client in this market. In other words, Joost designed the wrong product.

And that isn’t all. Beyond the fact that having to use a client to watch video is less-than-compelling to most consumers, Joost also failed to acquire compelling content. As ZDNet’s Ryan Stewart observes:

“Aside from a couple of niche shows, Joost just didn’t have the content draw that a site like Hulu has. Content is king and new content seems to be in demand. Joost couldn’t keep up.”

Will Joost’s new web-based player and efforts to shore up its content offerings help it better compete?

While it’s far too early to write Joost off as a failure, it’s pretty clear that Joost has its work cut out for it and that its competitors have established a strong lead in the market.

What Joost does demonstrate quite well is that continual success for serial entrepreneurs is difficult to accomplish. Despite having the brains, experience, track record and money, Janus Friis and Niklas Zennström have thus far found their efforts with Joost to be far less fruitful than their previous efforts with KaZaA and Skype.

This, of course, isn’t a knock on them as most new companies don’t have a Skype-like outcome.

Glenn Kelman, the CEO of Redfin and himself a serial entrepreneur, discussed serial entrepreneurship last year, noting that “every Silicon Valley colossus…was started by a first-timer 30 or under.

The truth is that there is no formula to success when it comes to starting new companies, especially in the fast-paced world of technology. Factors beyond an entrepreneur’s control contribute to success and any entrepreneur who dismisses the existence of luck probably overestimates his own skill.

And while Sarah Lacy named her less-than-compelling story about Web 2.0 “Once You’re Lucky, Twice You’re Good,” the reality usually is that once you’re lucky, twice you’re really lucky.

While I will not be surprised if we haven’t seen the last of Janus Friis and Niklas Zennström, venture capitalists and investors thinking that the third time is still the charm might want to consider that those who have been “lucky” twice should be able to purchase their own chips for the third spin of the roulette wheel.