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                              KEYNOTE SYSTEMS, INC.
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                                                                February 9, 2009

Fellow Stockholders:

     I am writing you to encourage you to vote in favor of our proposal to
extend the term of our 1999 Equity Incentive Plan at our Annual Meeting of
Stockholders on February 27.

     For Keynote, equity incentives, particularly in the form of stock options,
are a critical means for us to attract, incentivize and retain the employees
that are critical to growing our business and delivering value to our
stockholders.

     We understand that ISS/RiskMetrics will recommend that stockholders vote
against our proposal to extend our 1999 Equity Incentive Plan until December 31,
2011, primarily because we have a relatively large number of outstanding stock
options and ISS/Risk Metrics financial models show these options as having a
high computed value relative to our market capitalization. However, I encourage
you to look a bit deeper at Keynote's truly unique situation:

o    We are well within the "burn rate" guidelines established by
     ISS/RiskMetrics for our industry, and do not anticipate exceeding these
     guidelines in future periods.
o    We do not have excessive pay practices for our executive officers, and
     believe we are quite conservative in our compensation policies.
o    We cannot reprice options without obtaining stockholder approval.
o    Since our IPO in 1999, we have not amended our equity plans to increase the
     number of shares available for issuance and in fact in order to stay within
     "best practices" eliminated the "evergreen" provisions of our plans and we
     are not seeking to add shares to our equity pool.
o    While we have options to purchase approximately 5,800,000 shares of common
     stock outstanding as of January 31, 2009, over 90% of these shares are out
     of the money.

     So while we temporarily have a large number of outstanding stock options,
we believe their actual realizable value based on the actual exercise prices is
significantly lower than indicated by ISS/RiskMetrics models. We also expect the
amount of options outstanding to decrease over time given the relatively large
number of underwater options that will be expiring in the near future or may end
up being exercised in the event our stock price increases.

     At Keynote, we are intently focused on enhancing stockholder value:

o    We have returned to stockholders a large portion of our available cash
     through our stock repurchase programs. In fact, an important reason for the
     large overhang is the reduced number of outstanding shares resulting from
     our repurchases.
o    We have enhanced the value of our business through our acquisition of
     Keynote SIGOS, which has vaulted us into the leading position in the mobile
     testing and monitoring market.
o    We have transitioned away from our single page Internet measuring lines and
     have grown our broadband, multi-page services.



     As a result, we delivered outstanding results for stockholders last
quarter, our 9th consecutive year of generating cash from our operations. We
believe this was due in large part to the quality and hard work of our
management and employees.

     We intend to be judicious in our use of equity to compensate our employees
and believe that we can work within the confines of the current pool of options
in our equity incentive plan.

     Thank you for your support of Keynote, and as always, please do not
hesitate to contact me if you have any questions about the proposal or Keynote.


                               Sincerely,


                               Umang Gupta
                               Chairman of the Board and Chief Executive Officer








                               Jennifer Bolt
                               Chair, Compensation Committee of the Board