Risk Factors 3 Inability to sustain growth or profitability, and any related impact of U.S. or worldwide economic issues on customer acquisition, retention and usage levels, advertising spend and credit and debit card payment declinesInability to acquire businesses on acceptable terms or successfully integrate and realize anticipated synergies Reduced use of fax services due to increased use of email, scanning or widespread adoption of digital signatures or otherwiseFailure to offer compelling digital media content causing reduced traffic and advertising levels; loss of advertisers or reduction in advertising spend; increased prevalence or effectiveness of advertising blocking technologies; inability to monetize handheld devices and handheld traffic supplanting monetized traffic; and changes by our vendors or partners that impact our traffic or publisher audience acquisition and/or monetization New or unanticipated costs and/or fees or tax liabilities, including those relating to federal and state income tax and indirect taxes, such as sales, value-added and telecommunications taxesInability to manage certain risks inherent to our business, such as fraudulent activity, system failure or a security breach; inability to manage reputational risks associated with our businessesCompetition from others with regard to price, service, content and functionalityInadequate intellectual property (IP) protection, expiration, invalidity or loss of key patents, violations of 3rd party IP rights or inability or significant delay in monetizing IPInability to continue to expand our business and operations internationallyInability to maintain required services on acceptable terms with financially stable telecom, co-location and other critical vendors; and inability to obtain telephone numbers in sufficient quantities on acceptable terms and in desired locationsLevel of debt limiting availability of cash flow to reinvest in the business; inability to repay or refinance debt when due; and restrictive covenants relating to debt imposing operating and financial restrictions on business activities or plansInability to maintain and increase our customer base or average revenue per userInability to achieve business or financial results in light of burdensome telecommunications, internet, advertising, health care, consumer, privacy or other regulations, or being subject to existing regulationsInability to adapt to technological change and diversify services and related revenues at acceptable levels of financial returnLoss of services of executive officers and other key employeesOther factors set forth in our Annual Report on Form 10-K filed by us on March 1, 2018 with the SEC and our quarterly report on Form 10-Q filed by us on August 9, 2018 with the SEC and the other reports we file from time to time with the SEC The following factors, among others, could cause our business, prospects, financial condition, operating results and cash flows to be materially adversely affected: