As previously announced, GP Investments Acquisition Corp., a
Cayman Islands exempted company limited by shares (GPIAC) entered
into an Agreement and Plan of Merger, dated May 16, 2017 (as
amended from time to time, the Merger Agreement), by and among
GPIAC, Lets Go Acquisition Corp., a Delaware corporation and a
wholly owned subsidiary of GPIAC (Merger Sub), Rimini Street,
Inc., a Nevada corporation (Rimini Street), and the Holder
Representative thereunder, to which, among other things, Rimini
Street will merge with and into GPIAC. On June 30, 2017, the
parties thereto entered into Amendment No. 1 to the Merger
Agreement (the Merger Agreement Amendment).

to the Merger Agreement Amendment the parties agreed to, among
other things: (1) amend the provision of the Merger Agreement
relating to cash payments to be made to former employees and
former service providers of Rimini Street who hold outstanding
options that have not been exercised by the first effective time,
(2) update the capitalization of GPIAC referred to in the merger
agreement to reflect the number of public shares redeemed by
GPIAC on May 25, 2017, (3) provide that the mutual closing
condition requiring a minimum of $50,000,000 of GPIAC available
cash includes (rather than excludes) the amount of $6,037,500
that will be paid in respect of deferred underwriting
commissions, and (4) delete the provision of the Merger Agreement
requiring GPIAC to adopt an employee stock purchase plan.

The foregoing description of the Merger Agreement Amendment is
only a summary, does not purport to be complete and is qualified
in its entirety by reference to the full text of the Merger
Agreement Amendment filed with this Current Report on Form 8-K as
Exhibit 2.1 and which is incorporated by reference herein.

Item 8.01.

Other Events

The Merger Agreement provides that GPIAs, Merger Subs and Rimini
Streets obligations to consummate the transactions contemplated
by the Merger Agreement are conditioned upon, among other things,
expiration or termination of all applicable waiting periods under
the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (the HSR
Act). On June 2, 2017, Rimini Street and GPIA made the filings
required to be made under the HSR Act. On June 28, 2017, the U.S.
Federal Trade Commission notified Rimini Street that early
termination of the waiting period under the HSR Act was granted,
effective immediately. Therefore, the closing condition of the
Merger Agreement relating to the expiration or termination of the
applicable waiting period under the HSR Act has been satisfied.

Forward Looking Statements

Certain statements included in this communication are not
historical facts but are forward-looking statements for purposes
of the safe harbor provisions under The Private Securities
Litigation Reform Act of 1995. Forward-looking statements
generally are accompanied by words such as may, should, would,
plan, intend, anticipate, believe, estimate, predict, potential,
seem, seek, continue, future, will, expect, outlook or other
similar words, phrases or expressions. These forward-looking
statements include, but are not limited to, statements regarding
the proposed transaction between GPIAC and Rimini Street. These
statements are based on the current expectations of GPIAC and
Rimini Street management and are not predictions of actual
performance. These statements are subject to a number of risks
and uncertainties regarding GPIACs and Rimini Streets respective
businesses and the transaction, and actual results may differ
materially. These risks and uncertainties include, but are not
limited to, failure to achieve the necessary shareholder approval
for the proposed extension of the date by which GPIAC must
consummate an initial business combination; changes in the
business environment in which GPIAC and Rimini Street operate,
including inflation and interest rates, and general financial,
economic, regulatory and political conditions affecting the
industry in which Rimini Street operates; adverse litigation
developments; inability to refinance existing debt on favorable
terms; changes in taxes, governmental laws, and regulations;
competitive product and pricing activity; difficulties of
managing growth profitably; the loss of one or more members of
GPIACs or Rimini Streets management team; the inability of the
parties to successfully or timely consummate the proposed
transaction, including the risk that the required regulatory
approvals are subject to unanticipated conditions that could
adversely affect the combined company or the expected benefits of
the transaction or that the approval of the stockholders of GPIAC
and/or the stockholders of Rimini Street for the transaction is
not obtained; failure to realize the anticipated benefits of the
transaction, including as a result of a delay in consummating the
transaction or a delay or difficulty in integrating the
businesses of GPIAC and Rimini Street; uncertainty as to the
long-term value of GPIAC common stock; the inability to realize
the expected amount and timing of cost savings and operating
synergies; those discussed in GPIACs Annual Report on Form 10-K
for the year ended December 31, 2016 under the heading Risk
Factors, as updated from time to time by GPIACs Quarterly Reports
on Form 10-Q and other documents of GPIAC on file with the
Securities and Exchange Commission (SEC) or in the joint proxy
statement/prospectus that will be filed with the SEC by GPIAC.
There may be additional risks that neither GPIAC nor Rimini
Street presently know or that GPIAC and Rimini Street currently
believe are immaterial that could also cause actual results to
differ from those contained in the forward-looking statements. In
addition, forward-looking statements provide GPIACs and Rimini
Streets expectations, plans or forecasts of future events and
views as of the date of this communication. GPIAC and Rimini
Street anticipate that subsequent events and developments will
cause GPIACs and Rimini Streets assessments to change. However,
while GPIAC and Rimini Street may elect to update these
forward-looking statements at some point in the future, GPIAC and
Rimini Street specifically disclaim any obligation to do so.
These forward-looking statements should not be relied upon as
representing GPIACs and Rimini Streets assessments as of any date
subsequent to the date of this communication.

No Offer or Solicitation

This communication is not intended to and does not constitute an
offer to sell or the solicitation of an offer to buy or an
invitation to purchase any securities or the solicitation of any
vote or approval in any jurisdiction in connection with the
proposed business combination between Rimini Street and GPIAC or
otherwise, nor shall there be any sale, issuance or transfer of
securities in any jurisdiction in contravention of applicable
law.

Important Information For Investors And Stockholders

In connection with the transactions referred to in this
communication, GPIAC expects to file a registration statement on
Form S-4 with the SEC containing a preliminary joint proxy
statement of GPIAC and Rimini Street that also constitutes a
preliminary prospectus of GPIAC. After the registration statement
is declared effective GPIAC and Rimini Street will mail a
definitive joint proxy statement/prospectus to stockholders of
GPIAC and stockholders of Rimini Street.

This communication is not a substitute for the joint proxy
statement/prospectus or registration statement or for any other
document that GPIAC may file with the SEC and send to GPIACs
stockholders and/or Rimini Streets stockholders in connection
with the proposed transactions. INVESTORS AND SECURITY HOLDERS
ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS AND OTHER
DOCUMENTS FILED WITH THE SEC CAREFULLY AND IN THEIR ENTIRETY WHEN
THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT
INFORMATION. Investors and security holders may obtain free
copies of the joint proxy statement/prospectus (when available)
and other documents filed with the SEC by GPIAC through the
website maintained by the SEC at http://www.sec.gov. Copies of
the documents filed with the SEC by GPIAC are available free of
charge by contacting GPIAC at 150 E. 52nd Street, Suite 5003, New
York, New York 10022, Attn: Investor Relations.

Participants in the Solicitation

GPIAC and its directors and executive officers and other persons
may be may be considered participants in the solicitation of
proxies with respect to the proposed transactions under the rules
of the SEC. GPIAC and Rimini Street and their respective
directors and certain of their respective executive officers may
be considered participants in the solicitation of proxies with
respect to the proposed transactions under the rules of the SEC.
Information about the directors and executive officers of GPIAC
is set forth in its Annual Report on Form 10-K for the year ended
December 31, 2016, which was filed with the SEC on March 16,
2017. Additional information regarding the participants in the
proxy solicitations and a description of their direct and
indirect interests, by security holdings or otherwise, will also
be included in the joint proxy statement/prospectus and other
relevant materials to be filed with the SEC when they become
available. These documents can be obtained free of charge from
the sources indicated above.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits