Recap of the last 3 weeks in Silicon Valley:

(0. In March, Draw Something (50mm mobile users) was acquired by Zynga for $200mm. Cheap compared with the deals of April...)

1. Instagram (40mm mobile users) was sold to Facebook for $300mm cash and $700mm in stock -- worth at least $1 billion on May 17 when Facebook IPO's.

2. Path (2-3mm mobile users) raised $40mm. Its valuation is $250mm.

3. BranchOut (25mm users, mostly mobile) raised $25 million. It's worth $250mm despite having only one mobile employee.

4. Evernote (27mm mobile users) is raising $100m. It's worth $1 billion.

5. Square is raising $250mm. It's worth $4 billion.

Oh, and Pinterest, which isn't raising but is also worth at least $1 billion, has millions of mobile users. (Fascinating: Pinterest itself was a pivot -- the Phoenix that arose from a not-quite-good-enough iPhone "Shopping Mall" app! But I digress...)

What's the common theme here?

Mobile services that achieve momentum are worth a fortune.

Mind you, the number of great mobile services with momentum is still small. Besides the ones above, there's Facebook, Twitter, Angry Birds, Flipboard, Foursquare, Dropbox, Instapaper, and Pulse.

Hundreds of thousands of mobile apps will never break out.

But those that do are worth billions.

Additionally, Pinterest apparently doesn't really have a lot of original photos uploaded from its mobile apps, which seems like another huge untapped opportunity.

True, the original photos usually go into Facebook, Twitter, Instagram, Tumblr, Evernote, and Path instead.

I guess users like Pinterest for curation, not scrapbooking.

Henry Blodget explains why Google should spend $2 billion on Pinterest.

Then he makes a more emphatic case.

He points out that Google blew its opportunity to buy Twitter.

He also says LinkedIn should buy BranchOut.

And he points out that Twitter wanted to buy Instagram but could not afford it.

BusinessInsider thinks Larry Page needs to get out more.

We live in interesting times when a startup like Evernote wants to build a company that will last 100 years.

One thing all of the above companies have in common is patient investors.

Patient investors are hard to find, but they can make a huge difference to a company's success.

And it's all just beginning.

I do get that sense, Sergey.

I also believe the early mover advantage is over -- above are the winners.

I also note that it's possible to start from scratch in 2012 and create a hit.

Draw Something went from 0 to 50 users in 50 days.

Camera+ and SmugMug released into an already-crowded market and found huge success.

...or are we at the end of the mobile / social cycle?

More billion dollar startup valuations are happening now than at any other time in history.

Arguably, OMGPOP sold too early. It might have been worth $1 billion if it had been patient: http://articles.businessinsider.com/2012-03-21/tech/31218762_1_zynga-app-mobile-game

It took AOL 9 years to get a million users.

It took Facebook 9 months.

It took Draw Something 9 days.