Even making a 100th of what he does (maybe even a 1000th) would be enough for one person. Guess what - this happens everyday on the internet.
If you want to build a google, a microsoft, a paypal or something bigger its going to be hard for one person. From the investors perspective they want companies to generate a lasting difference to people's lives. Doing that as a one man band is hard. Generating monetary value for yourself is the flipside to this. But then who needs investors.
Ivan i disagree with you.
Creating a cash-generative site and then selling it - or keeping it on the side to supplement building other ventures in the future is a great option. I'm very much thining about this right now.
Why? Say you created successful online web service. Alone. Than, accidentally (ex. caterpillar behind the next corner) something fatal happen to you. Who will care about running business. Do you think that by ex. PG has appetite to search for new business owner and maintainer? It's not possible to simply jump in the running train if you know nothing about business internals and by Murphy's law one day after your death application stops working due some old, forgotten bugs. Take any Y sponsored site and ask PG what he knows about its source code. This is IMHO the only reason why VC's encourage you to find a co-founder. I'm running my sites alone and still have not a feeling of burn-out :) If you don't have enough skills to implement your idea, employ someone, if you don't have enough time to work on business, employ someone.
Now think about it. If your online business idea is something what cure your customers' pain, you don't need VC's capital to be sucessful. We are living in age of blogs and other wonderful viral marketing tools. Cheap hardware and hosting. Everything what you need is courage, kind community and forget arrogance.
I don't want to say that have a co-founder is bad thing. I just want to say that this must have reason and that reason should not be the VC's opinion.
BTW: find a dependable co-founder is like find a needle in hay stack :)
BTW, I'm saying this as someone who is going it alone, even though it makes things riskier.
It's all in the details. Let's say we have the same success rate for single founder and multiple founders ventures. There are many more multiple founders startups for at least two reasons: (1) it takes some guts to go alone and (2) VC/angels won't fund solo undertakings. Since the multiple founders pool is bigger, there are more successfull startups of this kind. Here you've got your misleading statistics.
Like the silly age debate, I guess it all comes down to this: do what you can with what you have. I certainly think that there is some 'cargo cult co-founder searching' going on around here, meaning that you shouldn't just grab a warm body because PG said so, but you should already know that person by the time you're ready to go. And if there isn't a someone, well, tough, do your best in any case... that's where I'm at.
p(success | more than 1 founder) is higher than p(success | only 1 founder)
If you can't find a founder that fits well with you, and that you can trust not to screw you at the first opportunity, then going it alone is the only option. But, I'd recommend trying to find a co-founder. Sure, you can build a successful business solo...but it gives you much worse odds.