We've invested in both San Francisco and New York startups, and New York impresses me more and more in terms of ideas and quality of the startups. But I've still got to give the clear advantage to San Francisco simply because of the network (investors, other entrepreneurs, schools, bloggers, etc).

I think there's something to Branch CEO Josh Miller's notion of New York "keeping things real", as it were -- but I also think that may lead to more hardship that simply isn't necessary.

Realistically each city has its strengths. There are a set of areas/companies that are better off started in NYC that utilize relationships with the cities industries - Advertising, Finance, Fashion, Sports, Publishing etc... Additionally, companies in the LBS space or rely on early communities with population density benefit from being in NYC.

There are enough investors, other entrepreneurs here to support a strong ecosystem (not as many as SF obviously).

One of the concrete things I love about NY is that tech (at least for a very long time) won't ever be the dominant industry in town. Like David said, the startups from NY are informed by all these other industries in both direct and indirect ways and I think that makes for interesting hybridization.

In another way, it also insures that the nerds (of which I am one) are never the coolest kids in school. I think weird things start happening when the nerds are also the homecoming kings.

It's true that San Francisco has a deeper bench. More money, more experience, more context.

What we get in NY instead is more collaboration, more peer-to-peer learning, more self-governance. There is a lot of room to grow and explore in NY right now and a lot of smart, able people here to help you do it. Our youth, our yearning, our sharing and self-direction....I see NY as a young Jimi Hendrix: self-taught, but doing incredible things because of it.

and +1 to what Jason is saying :)

Ev and I visited NYC in March 2011 prior to restarting Obvious. And we talked about the idea of doing something in NY. But ultimately it made no sense because of the network strength in SF.

Google's impact on accreting talent can't be overstated. It made building a company like Twitter possible (where 2/3rds of its founders and CEOs are ex-GOOG.)

So as companies like Tumblr and Foursquare reach that maturity they will have similar impact on the tech network for NY. It's coming together.

To that point, if you are dependent upon close relationships with the big platform companies (Google, Facebook, Twitter, Apple etc), you need to be in SF... Being in NYC is a disadvantage. In the same way leveraging NYC's industries is easier when you are a cab ride away. I think FourSquare utilized Madison Ave, which was not directly tangential to their core business, in a way that allowed them to destroy MyTown and Gowalla (partnerships with Bravo, Zagat, Thrillist, History Channel)...

The major pros and cons to have been well captured above, so I'll add one on work-style.

One of the things I always appreciated about the east coast is the direct communication in relationships. In NYC (or Boston) someone will tell you directly there isn't a deal to be had or that it doesn't fit into their current focus. Too many people in SF want to be liked and inclusive which means leading people on and potentially harming a business by having them spend cycles in areas with no opportunity.

I agree with David's point that it has more to do with what type of business you want to build and which city has a richer environment for that.

However, I would challenge that platform-based companies need to be in SF. At Twitter some of our closest relationships are with companies in NYC. It's easy enough to travel these days and you can really only meet so often, being around the corner doesn't change that. Being local does increase the likelihood of casual meetings outside of the office.

Is that true in all cases? Do you think Etsy, Tumblr and Foursquare have suffered from not being in SF?

I think that if you want to be close to the companies above, being in SF makes sense... I think the same is said for NYC and FourSquare, Tumblr, Etsy... If you want to be friends with them, seeing them a lot helps...

NYC tech scene has changed in just 5 years - this question itself is example.

Why? Because tech came to the industries that manhattan thrives on - publishing, fashion, advertising, media. Bec banks were no longer cool to work at anymore. Bec front end and mobile products require diff eng skills than chips, algorithms" that SV grew up on.

I'd like to see NYC make it past a business cycle. When the NPV of startups is lower, you get better sense for culture - even in bay area this holds true.

Hunter's point about how application platforms have changed the means of product development is really good. It may be hard to remember, but when Twitter chose SF as its home in 2007 it was counter-intuitive. We got pushback from folks who questioned our ability to hire Silicon Valley / CS engineers. This is less relevant now than it was then.

Also a good point on cycles. The folks who stick around when everything gets annihilated create the next cycle. Like in the Matrix!

All I know is if I walk into a party in SF and say 'SoLoMo' I end up in a two hour conversation about the future of mobile communication.

In NY I say the same thing and the response is 'Um...is that a neighborhood or a restaurant?'

Genuinely, I think the second environment is much healthier for building social apps for normal people :)

Agree with Hunter/Jason, NYC's key moment will be when things slow down, if the scene and the growth continues... But when things were super quiet here (2006-2009) - real companies like Etsy, SecondMarket, Gilt, Tumblr, FourSquare started...

@jonathan - sounds like you go to shitty parties. And why are you saying SoLoMo? :-)

@david - yeah, those early co's plus folks like meetup give strong core. Local VCs plus angels w tech exits in their pocket give me lots of hope. I grew up NYC suburbs and with all our family back east, I need it for my eventual return ;-)

@David I think you make a good point about the growth of new companies in the 2006-2009 era. The excitement of the burgeoning scene made NYC seem a scruffy underdog. Right now, as much as I love the idea that there's a ton of energy in the start-up world, the number of people trying to be "cool" by doing a start-up or exploring the entrepreneurial spirit for the sake of that exploration as opposed to solving a real problem with a new product is starting to create a frustrating environment.

@David @Dan I agree that it's hella frothy right now. And it will be good to see who's left standing when things shake out.

That said, one of the reason New York has exploded is because companies here don't have to be a pure tech play. On the contrary, some of NY's biggest success stories were media companies that used new technology and the explosion online to innovate around content and its delivery. See: Gawker Media, HuffPo, Buzzfeed. The other reason, as Tisch mentioned above...

@Rachel I think that's one of the things I love about NYC tech. As Jonathan mentioned above, you're not just in the room with a bunch fo developers or tech nerds, you're with groups of people who bring all sorts of talent to the table, sometimes even in industries you'd least expect. Looking at the people we've been fortunate enough to collaborate with recently has lead to solving problems in spaces from fashion to construction to content to fitness.

...is that NYC has a confluence of industries. Which means a lot of people thinking on a variety of different itches and how they might be scratched, by using (or inventing) new technologies. This brings a ton more diversity into the scene - including women! It's not an accident that there are tons more women-founded companies here in New York. See Betabeat: betabeat.com
The conversation above has been about all sorts of factors relevant to building companies...

...funding environment, access to tech talent, relationships to big platform companies. But the biggest factor impacting the number of women starting companies in New York is, I think, just that so many of them come by their ideas as a result of living, working and doing in this city.

Also on a more general level, I think that diversity makes for a better environment to build anything.