[wheels]

That's orthogonal to what waxy said. Public stock can vest as well. The liquidity of the stock is only relevant at which point it vests. So, if, as suggested, ZNGA were to lose some percent of its value before the first cliff hits, the effective value of the transaction would that percentage of the sticker price in an all stock deal.

[swombat]

Would an investor in startup X accept vesting stock from company Y as a payment for their stock in company X? Surely for investors, the stock has to vest immediately (if it's paid in stock)... It doesn't make sense to try and "keep the investor around", does it?

[benatkin]

Yes, but it would make for a less impressive deal. OMGPOP being acquired for much less is plausible, so another kind of a less impressive deal is plausible too.

Zynga could go bust. Without being acquired OMGPOP could go bust. So the investor would have to weigh the risk.

I also think there would have to be some cash and/or stock that would be available right away, for it to be an enticing deal.