When you buy stock in a public company (like Google, or Apple) you do not receive a paper stock certificates. Corporate stock ownership is managed electronically.
That is not true for privately held companies. If you invest in a tiny two person private company, or an enormous private company (like Twitter or Square), you still receive a paper stock certificates in the mail.
eShares is the first SEC registered transfer agent for privately held companies. eShares eliminates the need for paper stock certificates by converting the entire process to electronic form. From now on, private stock issuance and management is all done online.