ReadWriteStart

Y Combinator is already known as one of the most successful startup incubators in the tech industry. But just how successful is YC? And how successful are the 316 companies that have gone through the program?

According to co-founder Paul Graham, very successful. The combined value of the top 21 startups that have graduated from the program is $4.7 billion.

A number of new startup accelerator and incubator programs have popped up lately, a response no doubt to the success of the Y Combinator and TechStars programs and the success of the programs' participants. At some level, many of these programs offer similar features: networking, mentoring, office space, and funding.

Many of these new programs are modelled on YC or TechStars, but that doesn't really guarantee their success. So in order to help entrepreneurs have a better understanding of which programs were really worth the time and effort, Aziz Gilani from DFJ Mercury, working in conjunction with Tech Cocktail and the Kellogg School of Management, undertook a research project to actually rank the accelerator programs in the U.S.

Startup School is an annual event co-sponsored by Y Combinator and BASES, Stanford University's Business Association for Entrepreneurial Students. Today's Startup School, now in its sixth year, was a day full of speakers, imparting their knowledge to a packed auditorium of entrepreneurs.

The topics at Startup School ranged from the history of Silicon Valley innovation and the history (and future) of startup funding, to testing your hypothesis, pivoting, and optimizing for happiness. The speaker - 11 all told - gave presentations, followed by a short Q&A with audience members.

When startups fail and are forced to shut down, often times one of the co-founders will offer a short blog post about what happened and why the company wasn't able to succeed. Not everyone does however, as reveling in your own failure isn't the most fun thing to do. In the case of the failed individual journalism platform NewsTilt, co-founder Paul Biggar penned a 7,000 word essay last week that painstakingly details how and why his company ultimately failed, providing a must-read set of lessons for any entrepreneur.

As someone with limited (ok, minimal. ok, zero) technical background, I am sympathetic to those entrepreneurs who are looking for co-founders in order to help them build and launch their startups. Sometimes you don't have the right skills to do so on your own.

But often you do, and the time spent searching for a co-founder could instead be funneled into developing the business. That's the argument, in part, of Ray Grieselhuber, the single-person founder of the SEO automation and analytics startup Ginzametrics.

In the latest example of VC chatter - wherein multiple venture capitalists simultaneously blog about a hot issue - the topic du jour is the debate between convertible debt and equity rounds. The spark came from a Friday night tweet by Y Combinator founder Paul Graham (yes, he finally joined Twitter) that declared convertible notes victorious since each of this summer's YC class opted for them. This morning, several VCs have weighed in on the issue, so here's what entrepreneurs and early-stage startups need to know about the debate.

At Tuesday's Demo Day, the latest batch of Y Combinator startups raved about the experience, the guidance, the resources, the networking that their participation in the incubator program gave them. As of today, YC startups can add another benefit to that long list: priority access to some of Facebook's technologies.

Today was Demo Day at Y Combinator, where the latest batch of YC startups had an opportunity to showcase their products and make their pitches to a packed room of investors and journalists.

This was the 11th Demo Day for Y Combinator, and the incubator program has graduated 208 startups in its history, with 36 in this summer's cohort - the largest to date.

The startups' products vary, as do the stage their businesses are at: some are already profitable, some have yet to launch. Those that haven't launched remain "off the record," but here are the names and brief descriptions of those we can tell you about:

A group of Australian tech investors and entrepreneur have formed a new seed fund that will offer a Y Combinator-style incubator model, with small early stage investment and up-close mentoring to Australian startups.

Startmate will hold its first program in the first quarter of 2011, and the application process will begin in October Startmate plans a three month program with five selected startups and will offer a $25,000 investment, mentorship from a long list of successful founders, and a two-week trip to Silicon Valley. There will be two demo days at the end of the program - one in Sydney and one in Silicon Valley, where participants will present in front of early stage investors.

The hot movie at theaters right now is the mind-melting thriller Inception in which thieves steal ideas by entering people's subconscious by way of their dreams. The thing about our subconscious is that it is at work even when we are awake and it can affect the nature and focus of our thoughts. For startups, maintaining focus on the most important goals of your company is imperative to success, and Y Combinator founder Paul Graham says he has learned to train his brain to do just that.