I've found that people have wildly different ideas about both the reason to do a startup, how to execute, what's important, and where to exit. There's a great diversity even among people who know/read a lot about it. In fact, I'm amazed that the multiple founder system works at all. Except for cases where everybody is a college friend or something, it looks like a recipe for a lot of conflict.
The question is not whether or not you and your cofounder disagree. The question is whether you can nonetheless find a way to make decisions and move on. If every disagreement causes your progress to stop dead, you've got a problem. If every disagreement is resolved in favor of the person with the loudest voice, you've got a problem. But it is in fact possible to make progress even with a team full of people who disagree, provided everyone is sufficiently open-minded, mutually respectful, and willing to indulge in whimsical experiments.
A lot of startup stories contain moments in which the cofounders had big disagreements; e.g. the time when Steve Wozniak had to be dragged kicking and screaming into quitting his day job with Hewlett-Packard.
What I've found, however, is that cofounders are especially tricky to integrate. I think once you have a running app/business it gets easier, but that entire process of taking something fuzzy and making it concrete is just a very difficult process for some folks. People are really good at BSing! Heck, if there was a prize for sitting around talking about startups it'd be a big bunch of folks winning it (myself included at times). But once you move past idle talk and start feeling for a market and a problem? It's not so sexy any more. And then when you're talking about all the hours that's required? People have a tendency to melt into the woodwork.
The ones that are extremely motivated are usually that way because they're emotionally attached to some concept -- and that concept may or may not be workable in the market. Which means it's like pulling teeth trying to have an honest conversation about viability.
Then there are the technology bigots, of course, and the "idea" guys.
I don't know about other startups, but the one I'm working on now is a pretty big commitment -- big enough that my "day off" is basically taking a long lunch today and surfing HN. The rest of the week, day and night, I'm working.
I don't see that combination of willingness to work on something that might not be hot at first and also being able to pivot when needed as being very prevalent. It's probably just me, though.
“Genius is 1% inspiration and 99% perspiration!” - Edison
(I'm behind both)
This is true only of American dating sites. A number of Indian dating sites are based on that exact model.
I guess the lesson to take from that is this: if your expectations are low enough, and social pressures not to quit are strong enough, any reasonable pairing can be made to work.
To me, first and foremost, the fact that you don't have any out of pocket expenses is a good thing, it eliminates one barrier to entry. Virtual companies achieve that. In comparison, joining a "real" incorporated startup as co-founder, the first thing you do is split the legal costs and buy your shares. So right there, a few thousand dollars before you even know if you should work together. And there is no "undo" button, unlike virtual companies.
That's also why in the co-founders meetup I ask the presenters to not only present their business, but reveal a bit of their own personality. I believe that compatibility as co-founders comes equally from being passionate about the same things but also being compatible personality-wise (read this http://blog.fairsoftware.net/2009/11/19/first-co-founders-me... for more on the topic).