Question to these many companies who relaunch their websites and then let them rot for 2-3 years, just to plan another big relaunch... can you remember a Google relaunch? Or an Amazon relaunch? No? Probably that's because there was none.
They keep working on the product continously - and with frightening speed. 890 changes is close to three a day. Including Saturdays and Sundays. And holidays.
Constant improvement is critical. And to honour Google's 10 year anniversary of their IPO: Here's their 10 biggest changes since going public: