Using their own stock helps them compensate Google for how much they feel Mobility is worth without putting themselves in a tough liquidity position etc.

Tangentially related to this transaction you may or may not be aware that pretty much any company that funds its own insurance (most large companies) are required by law to hold investments that will help carry them over for any insurance claims. So there is some fund they hold that has stocks, bonds, etc. set aside so that they are covered for insurance claims. The same is true of pension funds.

[EDIT] Oh, and they have a 5% stake in lenovo, which should benefit android and chromeos (and maybe keep MS in check).

Giving money back to shareholders is relatively easy, raising it from them if you need it for something is more involved.

And if you're going to hang on to it in some relatively liquid form, you might want to try and get a better return than you would from sitting on a pile of cash.

- you want a seat at the board or at least a hotline to someone up the chain in a key partner company. This will give you insight and influence in your key partner's plans, health, future products, as well as CI.

- drive costs down. Buying a stake in a supplier doesn't necessarily mean you will pay less, but you get some of it back through your stake.

- getting access to know-hows/technology/ consulting/distribution.

- reimbursement for know-hows/technology/consulting/distribution. i.e. you a have substantial distribution channel in a vertical market, but developing it does not align with your focus. You can sell it at a big discount, squeeze it as much as you can, or lease/sell it to a company which will find a tremendous persistent value in it. Compensating you according to the value they gain in hard currency is difficult, even impossible for smaller companies. Getting equity or options in the partner company while leasing/selling your asset to them will ensure you get maximum value out of an under utilized asset.