In google if you are really good you could maybe get promoted every 1.5 years, but realistically this is probably more like every 2-3 years.

Your pay then gets bumped to the next grade (or whatever grade you move in to in cases where you transfer laterally) and from what I can tell the increase can be 20-30% increase.

You also will get regular stock option/unit refreshes each year based on performance, so those will start to add up over the years and can be a substantial part of your income assuming the stock is doing ok (and historically it has).

To speak for the latter, Google's 10% across-the-board raise last year does apply to new hires, personally speaking. I'm surprised that my offer is above the MS median and average.