Fidelity investments is one of the investors of Innogames. That is all of Innogames not just the game of grepo. Since Fidelity is an investment firm they post all of there investments are required by the SEC (U.S. Security Exchange Commission). Investors have this problem of wanting to know where there money goes. So, companies that are publicly traded release information (somewhat like a business plan). This plan shows how much money the company has made last year, 5yrs & 10yrs ago. It also shows how much money they want too/ plan too make in the next 1,5,10 years and what directions they plan on taking.
Sadly, you are right that there are people that spend thousands of dollars on this game. So innogames actually has to spend $13 million last year in lawsuits. Because take for example (the example they use in there investor portfolio) that discusses the kid that spent $40k in 2 months on playing one of there games. The credit card company and the parents of the kid who stole the credit card sued innogames. Of course innogames did end up losing the lawsuit, but also appealed it. which will cost more money. But they did not go to court over the 40k. they went to appeals because it set the precedent for future lawsuits. And believe me.... they have a lot of people claiming there credit cards were stolen in used to play innogames. This is also one of the reasons why innogames went to paypal as a form of payment 2years ago. It cuts down on innogames liability.
But the answer to the other half of your questions is yes, while they do get a lot of money from players spending money and have over 50 million registered users since they innogames was born in Aug 2003 (although that is total users, not active accounts). companies (like the one used in there forecast) discusses investors that invest millions i.e. fidelity, Turk, etc etc. Invest millions into innogames per year. Fidelity has invested over $80 million alone into Innogames since 2010. Now i use fidelity Investments as an example of one investor. They are not the largest investor in innogames and are only one of hundreds maybe thousands of investors. Heck, sony and microsoft are large investors. Not to mention, google is a big investor. Probably why they require google chrome to play Grepolis and other games. Which dont forget, it is a google malware you install on your computer when you play these games.
I do not know how much innogames makes off individual players spending money to play games vs. the amount of money they make of investors and Marketing.... but i am very confident that it is way more then what players spend. LOL! WAY MORE!