Learn how to make money with your product or it will get shutdown

Yahoo shutting down delicious should be a warning sign to all web product developers. Your product will get shutdown if it isn’t making money, period. Try to figure out how to make money as soon as you have a little bit of traction.
“Yes… but Delicious is different… it needs to be free!” 
No, it doesn’t. They have hundred thousand plus passionate users. Checkout pinboard.in – they are a competitor to delicious and they make money. Here is an awesome response to why they charge:

“The signup fee helps discourage spammers and defrays some of the costs of running the site.  

Thanks to the entry fee, Pinboard has remained spam-free since launch. Not having to expend resources on spam fighting means having more time to work on features, and keeps the site fast and small.

I’m really happy that YouTube, Flickr, and Imgur are all making money. Otherwise Google would have shutdown YouTube, Yahoo would have shutdown Flickr, and the Imgur guys would have moved onto something else. My guess on why Twitter is getting such high valuations is because their “Making Money” experiments seem to be working. I’m also really happy to see Reddit trying to make money, otherwise Conde Nast will shut them down.
The companies that can keep moving are the ones that bring in cash.2/1//2011 Update: Yahoo Shutdown MyBlogLog. A company they purchased but doesn’t bring in any cash. Also checkout 37 Signal’s “What happens after Yahoo acquires you” blog post.