[hacklite]

    "Google has a dual-class share structure that gives Larry Page, Sergey
    Brin, and Eric Schmidt de facto total control over the company, and 
    investors certainly haven't avoided Google's stock as a result.

    Yahoo does not have a dual-class share structure, and it's too late to put 
    one into place now.

    If Yahoo did have a dual-class share structure, Yahoo's cofounders would
    have been much better situated to block Microsoft from attempting a 
    takeover.

    You can bet that this is being noticed by the founders of every technology
    company that might go public from here on out."

Does YC structure things this way?

[ivankirigin]

These two classes are for public stock offerings. YC companies might choose this type once they go public. Broadly, stock in YC companies is either common like the shares for the founders, employee options, or they're preferred, which is often what investors own. There are specific benefits to preferred stock - different depending on the terms of the deal.

Control in a startup is largely determined by percentage ownership and and the composition of the board.

[dhs]

"If Yahoo did have a dual-class share structure, Yahoo's cofounders would have been much better situated to block Microsoft from attempting a takeover."

Great cautionary tale: Yahoo's cofounders were really smart people with access vast information resources, yet they clearly missed at least two things, which may be prove to be fatal now. I must never assume that I know enough.