Is Rosetta Stone Inc (RST) A Value Trap?

Page 10 of 12

Page 9 of 11 – SEC Filing

EXPLANATORY NOTE

This filing constitutes an amendment of the Filers Schedule 13D, as amended, initially filed on August 21, 2014. The Filers no longer hold the
securities for the purpose of or with the effect of changing or influencing the control of the Issuer and have no intention of participating in any transaction having that purpose or effect.

Item 1.

(a) The name of the issuer is Rosetta Stone Inc. (the Issuer).
(b) The principal executive office of the Issuer is located at 1919 North Lynn St., 7th Fl., Arlington, VA 22209.

Item 2.

(a) This statement (this Statement) is being filed by John H. Lewis, the controlling member of Osmium Partners, LLC, a Delaware limited liability company (Osmium Partners), which serves as the
general partner of Osmium Capital, LP, a Delaware limited partnership (the Fund) and Osmium Capital II, LP, a Delaware limited partnership (Fund II), Osmium Spartan, LP, a Delaware limited partnership (Fund III),
Osmium Diamond, LP, a Delaware limited partnership (Fund IV) and Osmium Special Opportunity Fund, LP, a Delaware limited partnership (Fund V) (all of the foregoing, collectively, the Filers). The Fund, Fund II,
Fund III, Fund IV and Fund V are private investment vehicles formed for the purpose of investing and trading in a wide variety of securities and financial instruments. The Fund, Fund II, Fund III, Fund IV and Fund V directly own the common shares
reported in this Statement (other than the 135,472 shares owned directly by Mr. Lewis). Mr. Lewis and Osmium Partners may be deemed to share with the Fund, Fund II, Fund III, Fund IV and Fund V (and not with any third party) voting and dispositive
power with respect to such shares. Each Filer disclaims beneficial ownership with respect to any shares other than the shares owned directly by such Filer.
(b) The Principal Business Office of the Filers is 300 Drakes Landing Road, Suite 172, Greenbrae, CA 94904.
(c) For citizenship information see Item 4 of the cover sheet of each Filer.
(d) This Statement relates to the Ordinary Shares of the Issuer.
(e) The CUSIP Number of the Common Stock of the Issuer is 777780107.

Item 3.

Not applicable.

Item 4. Ownership.

See Items 5-9 and 11 on the cover page for each Filer, and Item 2. The percentage ownership
of each Filer is based on 21,882,727 shares of Common Stock outstanding as of March 8, 2016, as reported on the Issuers Annual Report on Form 10-K for the fiscal year ended December 31, 2015 as filed with the SEC on March 14, 2016.

Item 5. Ownership of Five Percent or Less of a Class

Not applicable.

Item 6. Ownership of More than Five Percent on Behalf of Another Person.

Not applicable.

Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company.

Not applicable.

Item 8. Identification and Classification of Members of the Group

Not applicable.

Item 9. Notice of Dissolution of Group

Not applicable.

Item 10. Certification

By signing below I certify that, to the best of my knowledge and belief,
the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a
participant in any transaction having that purpose or effect.

Follow Rosetta Stone Inc (NYSE:RST)

Page 10 of 12