This excerpt taken from the TLEO 8-K filed Oct 28, 2009.
Use of Estimates
The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States requires management to make certain estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements, as well as reported amounts of revenue and expenses during the reporting period. Significant estimates included in the Companys consolidated financial statements presented herein include the allowance for doubtful accounts, revenue recognition, including vendor-specific objective evidence (VSOE), and the fair value assumptions underlying the valuation of the convertible redeemable preferred stock instruments, stock options, and intangible assets, including determination of the useful lives. Actual results will differ from those estimates.