(2) Balance Sheet Account Details

Short-Term Investments

During the six months ended June 30, 2012, the Company purchased commercial paper, corporate notes and bonds and U.S. government agency securities, all with maturities of less than twelve months. The following is a summary of short-term investments at June 30, 2012 (in thousands):

As of June 30, 2012, the Company had certain available-for-sale securities in a gross unrealized loss position, all of which had been in such position for less than twelve months. There were no impairments considered other-than-temporary as it is more likely than not the Company will hold the securities until maturity or a recovery of the cost basis. The following table shows the fair values and the gross unrealized losses of these available-for-sale securities aggregated by investment category (in thousands):

For the six months ended June 30, 2012, gross realized gains were not significant and there were no gross realized losses as a result of sales of the Company’s securities.

Property and Equipment, net

Property and equipment, net consists of the following (in thousands):

Construction in progress consists primarily of leasehold improvements and servers, networking equipment and storage infrastructure being provisioned in our new third-party data center hosting facilities. Depreciation expense for the three months ended June 30, 2012 and 2011 was $2.8 million and $0.6 million, respectively, and for the six months ended June 30, 2012 and 2011 was $4.9 million and $1.0 million, respectively.

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consists of the following (in thousands):