15. Fair Value Measurement

We use a fair-value approach to value certain assets and liabilities. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. We use a fair value hierarchy, which distinguishes between assumptions based on market data (observable inputs) and an entity’s own assumptions (unobservable inputs). The hierarchy consists of three levels:

Determining which category an asset or liability falls within the hierarchy requires significant judgment. We evaluate our hierarchy disclosures each quarter. Assets and liabilities measured at fair value on a recurring basis are summarized as follows:

On August 30, 2013, November 25, 2013 and December 19, 2013, we entered into securities purchase agreements relating to the sale and issuance of convertible notes in the principal amounts of $200,000, $200,000 and $250,000. Each of the Convertible Notes are convertible into shares of our common stock, at any time after issuance, at the option of the purchaser, at a conversion price equal to $0.02, subject to adjustment upon the happening of certain events, including stock dividends, stock splits and the issuance of common stock equivalents at a price below the conversion price. Subject to our fulfilling certain conditions, including beneficial ownership limits, the convertible notes are subject to a mandatory conversion if the closing price of our common stock for any 20 consecutive days commencing six months after the issue date of the convertible notes equal or exceeds $0.04. The terms of the convertible notes meet the criteria for the bifurcation of an embedded derivative. Therefore, we recorded the fair value of the embedded derivative liability as of the issuance date for each of the convertible notes for an aggregate fair value of $243,889.

A discussion of the valuation techniques used to measure fair value for the common stock warrants is in Note 14. The accrued rent relates to a non-cash charge for the closure of our Anaheim, California location, calculated by discounting the future lease payments to their present value using a risk-free discount rate from 0.6%. The accrued rent is included within liabilities of discontinued operations and long-term liabilities of discontinued operations in our consolidated balance sheets.

The following table shows the changes in Level 3 liabilities measured at fair value on a recurring basis for the twelve months ended December 31, 2013:

*     Represents the estimated fair value of the office closures included in accrued and other long-term liabilities.