1. Branding. If Joe Blow is not using Google yet, he might just check it out, if he hears he should invest in it because his brother-in-law just made a killing with his Google shares.
2. Stock-options. Sooner or later those purist-idealistic Googlers will want to cash their stock-options, because with the second child coming its time for a bigger house. How do you value non-stock-market listed options? At 10 times PE?, at 20 times? What is fair?
Nice idea, maybe in two years time when everyone cannot do without, and maybe only for power business users with fixed IP's doing more than a threshold amount of searches a month.