Ik denk ik drop hem hier even:
What are some startup ideas that frequently fail?• Anything that makes programming "easy for non-programmers or businesspeople"
• Micropayments
• T-Shirts (except Threadless (and Busted Tees ... thanks Adam Kazwell))
• Recommendations based on what your friends like
• RSS readers, or more generally, sites focused primarily on presenting and formatting news stories gleaned from 3rd party sources
• Customized personalized newspapers focusing on mainstream news (as opposed to niche industry news with high business value)
• Find nearby people to meet/date through your mobile phone
• Anything involving paying people to look at ads
• Sites that purport to measure someone's trustworthiness as a standalone service, separate from any other context or functionality
• Craigslist killers - but not sites that attack individual categories on Craigslist (see diagram in this question's summary)
• To-do lists - there are tons of these, but everyone's workflow tends to be so personalized and specific to that person that none of them really catch on
• Most blogs that are started with the intent of being businesses
• Business that let consumers scan some kind of code, number or barcode in real life, with some special device, or lately their phone, and they get sent a URL, ad or coupon in return.
Moaar:
http://www.quora.com/What(...)that-frequently-fail