Google co-founder Larry Page said his first year back at the company's helm has been marked by big bets on social networking and mobile gadgets.

Page marked the anniversary of his return as chief executive of the Internet colossus by sharing his thoughts in a letter posted at Google+ social network.

"Since becoming CEO again, I've pushed hard to increase our velocity, improve our execution, and focus on the big bets that will make a difference in the world," Page said.

"Top of my priority list has been creating a simpler, more intuitive experience across all our products so users get exactly what they need, right when they want it."

Page told of reorganizing Google's management team to improve accountability and of kicking off "a big clean-up" that resulted in the elimination or consolidation of more than 30 products.

"Google has so many opportunities that, unless we make some hard choices, we end up spreading ourselves too thin," he said.

Many of Google's remaining products, such as its globally popular search service, were given cleaner, consistent and "beautiful" looks, according to Page.

"I have always believed that technology should do the hard work -- discovery, organization, communication -- so users can do what makes them happiest: living and loving, not messing with annoying computers," the Google co-founder said.

Page has made a priority of weaving budding Google+ network into the company's other properties such as search, Gmail and YouTube in what some onlookers have branded an obsession with challenging Facebook.

He bragged in his letter that Google+ has more than 100 million users and the amount of activity at the social networking service is ramping up.

Page described Android operating system for smartphones and tablet computers as being "on fire" with more than 850,000 devices activated daily.

More than 350 million people use Gmail and the number of people using YouTube monthly tops 800 million, according to Google.

"People rightly ask how we'll make money from these big bets," Page said.

"Over time, our emerging high-usage products will likely generate significant new revenue streams for Google as well as for our partners, just as search does today."

He gave the example of mobile advertising having a "hugely positive" effect on revenue.

Recent privacy policy changes to let user data be shared between Google services, while controversial, have led to a "better, more intuitive" experience, Page contended.

"We have always believed that it's possible to make money without being evil," he said.

"In fact, healthy revenue is essential if we are to change the world through innovation, and hire (and retain) great people. We work hard to explain what we are doing and why because with size comes responsibility."

Google rolled out its new privacy policy in March allowing the firm to track users across various services to develop targeted advertising, despite sharp criticism from US and European consumer advocacy groups.

The Mountain View, California-based firm said the changes are designed to improve the user experience across Google products, and give the firm a more integrated view of its users, an advantage enjoyed by Apple and Facebook.

Critics including European privacy agencies and US consumer watchdogs argued the new policy, which offers no ability to opt out aside from refraining from signing into Google services, gives the Internet giant unprecedented ability to monitor its users.

"We recognize that the changes we make, like our recent visual refresh, can initially upset some users -- even if they later come to love them," Page said.

"But we don't operate in a static industry and technology changes so fast that we need to innovate and iterate."