You'll need to develop a business plan for that, make a market analysis.

Decide on your market, is it a local, national wide, worldwide market? Decide on a product, look for similar products in your desired location / market. If you found one, how is your product better, if not, look for potential / close competitors [they are also called indirect competition]... a good businessman will say there is always competition, no such thing as 100% free of competition. Make sure there is a demand for that product, maybe there is low competition because the product has no demand?

Lets say you've found a product with demand and low competition, next decide on your monetization system, will it subscription, sale of CD or DVD... how you will make money?

Return to your desired location / market, compare economical status of those potential clients in the area with your product price, does it fit? Or are you selling luxury cars to Africa's general population?

Estimate your clients amount, is it enough to profit?

If after all this you come to a conclusion that you have found a market, product in demand with low competition or one that you can overcome, your price fits the market and there is enough clients to profit then congrats! Time to develop... dont forget to calculate development costs and marketing costs, your clients will have to find you somehow, otherwise your market analysis is useless.

If you found a problem along the way on market analysis, try to solve it by changing something... things like a different location. If you cant get it to work then the business idea is not viable.

This is a Business question, not a Game Design question. Moving.

glhf, you asked:
Q: How to estimate potential profits/revenue of your game?

A: Read lots of articles about your marketplace - how other games have sold, what kinds of things those games' creators encountered. Look up statistics the best you can.
http://www.researchandmarkets.com
http://www.marketresearch.com
http://www.abiresearch.com
http://www.vgchartz.com
http://archives.igda.org/faq.php#biz01
http://www.industrygamers.com
http://www.gamasutra.com
http://www.alexa.com/siteinfo/bigfishgames.com
http://www.gamesindustry.com/about-newzoo/todaysgamers_graphs_international
http://www.joysticklabs.com/the-quest-for-the-missing-app-data

Two case studies:
http://mikengreg.com/blog/2010/10/2-months-of-solipskier-app-store-sales/
http://struct.ca/2010/the-story-so-far/

Mobile:
http://mashable.com/2011/02/24/mobile-app-dev-cost/
http://communities-dominate.blogs.com/...its-bad-news-and-then-it-gets-worse.html

And write a good business plan before you spend any money.
http://sloperama.com/advice/lesson29.htm
http://lmgtfy.com/?q=how+to+write+a+business+plan

This is a Business question, not a Game Design question. Moving.

glhf, you asked:
Q: How to estimate potential profits/revenue of your game?

A: Read lots of articles about your marketplace - how other games have sold, what kinds of things those games' creators encountered. Look up statistics the best you can.
http://www.researchandmarkets.com
http://www.marketresearch.com
http://www.abiresearch.com
http://www.vgchartz.com
http://archives.igda.org/faq.php#biz01
http://www.industrygamers.com
http://www.gamasutra.com
http://www.alexa.com...igfishgames.com
http://www.gamesindu...s_international
http://www.joystickl...issing-app-data

Two case studies:
http://mikengreg.com...pp-store-sales/
http://struct.ca/201...e-story-so-far/

Mobile:
http://mashable.com/...e-app-dev-cost/
http://communities-d...gets-worse.html

And write a good business plan before you spend any money.
http://sloperama.com...ce/lesson29.htm
http://lmgtfy.com/?q...a+business+plan

You killed it Tom! Thanks for the list