I own two businesses that produce $6500 in monthly income for me and my family. However, a 3rd business is costing me $2300 a month to keep the operation going, but has grown 400% in revenue YoY. I have no personal debt and approximately $75K in the bank. What should I do with the 3rd business?

Do the math. The revenue growth is inspiring, but if you spend your savings to support the business without profits you're just gambling. If you really believe the business will continue to grow, and become a profit making concern, find someone with deeper pockets than you and sell a portion for enough to cover the period between today and when you expect the business to turn the corner. That's the calculation you need to do. How long are you going to be in the hole, how much runway do you need, how much is that going to cost? I've seen friends feed one successful business to another which is failing. Spending their attention and time trying to fix a failure, while the success they enjoyed withered. Don't let your ego prevent you from letting it go in whole or in part if that's the right decision.

You seem experienced and successful at building bootstrapped businesses.  The third business, as described, is not of that type. Given no knowledge of what it is, I'd suggest you consider two other options.  One, seek an acquirer, rather than an investor.  Someone who either has money an is looking for an idea, or a hungry first-time entrepreneur who can spend 80hrs per week to make it fly. Two, find an alternate model to your $500k raise, turning it into a bootstrapable business.  Can you toss it up on Kickstarter or Indiegogo to raise some presales capital?  Submit it to some contests and win some prize money? What I suspect is that investors will quietly say no to you because of your lack of focus.  Plus they'll discount your other two businesses as a) small and b) distractions. In poker terms, it's time to go all in or walk away.

Need more information - do you have other commitments, eg a mortgage, children? and what are your priorities ... not worth trying to get this answered on Quora, you need to have someone look at this who knows a lot more about what you need and want to do

Not all businesses start making money from the word go. So it's ok to build a business through it's initial loss making days. However you have not mentioned for how long your third business is running and for how long you are sustaining losses? What was your original business assumptions when you started it? Have they held true? From the time you started it and  where it is today, are you happy with the progress and how close it is to your initial estimations? In other words, if you had pitched this business idea to some investors when you contemplated it and had they invested with you, how happy would they be with its current state? Ask yourself these questions and try to answer them rationally. If your answers gives you gaps in performance, do you and your business got what it takes to fill and fix them? Also reassess your current assumptions about the business and its future. At the end of it all, if you still feel for this business and is reasonably confident about achieving growth and profits, then go ahead with the 3rd business. If you are not convinced then, put it on the block for sale. If you decide to go ahead with the 3rd business, then you have questions about the second business. It may not be making much money and is a low margin business but it is giving you some vital dollars that will help you cover the losses of the 3rd business for the time being. So don't sell it but run it as you planned. Promote an able hand to run the business. Also look for opportunities to reduce the cost there. Now comes the important factor, investment for your 3rd business? Where is it going to come from? Will this business generate any interest among professional investors? The money ($500k) is not big for them but then do you have a convincing business case for them to put it in your business? Think about it, and if necessary find a mentor who can guide you through this. Also look for someone who can join you in this business with capital and share risks / return. These are the best ways to fund additional investment requirements in the 3rd business. If you are left with no other option but to dig your own pockets, then consider selling the 2nd business. This is contrary to my advice in the second paragraph, but then with no other option this is your go to point. Remember, if your views about the second business is right, then not going ahead with your 3rd business would mean your personal income and growth prospects won't be great, unless you decide to improve your real estate business. So you got to bet on the horse, which you think would win you the race and that horse in your case, seems to be the 3rd business. But before selling the 2nd business, ensure you have done your homework well on the 3rd business and have covered the ground well. All the best.

It looks like you have already found your answer with what you wanted to do and given majority ownership to a 3rd party. I hope that you sold it to them or that they are handling all of the expenses and it wasn't just a "gift" so to speak. All that being said, why is there no focus on the real estate business? To me the second business seems like a really scary business. I realize that you are making a $30,000 a year profit but with a profit margin of only 5% it seems like if one small variable changes you go from being in the red to being in the black. Me personally for business number 3 if you think it had huge potential I would have reached out to VC or angel investors and tried to get the funding you needed and been able to take a salary of 80-100k per year build business number 3 then sell business number 2 and keep running the real estate. Unfortunately business #2 is only really earning you $30 an hour for your time spent which means it would be hard to hire out a quality person to fulfill your duties and still have the business turn a profit. This added to the fact of low profit margins and increasing competition makes me a little worried about business number 2. Again I keep going back to the real estate, you obviously did something right in that area unless the properties were just passed down through your family. I know it isn't as "sexy" as online business but right now you are earning roughly $1,000 an hour for the work you put in there. Why not expand that so that it is making $8k a month so that you can live completely off of that and work 10 hours a week then refocus on the other businesses.

From your update it looks like you found your answer to your third business by selling a majority share to someone who can build it.  My advice is to take care of your real estate business and keep building business #2.  Web based businesses can really take off so $600K can become $6M just with a few successful social or other media posts.

Try to run 1 business and sell the others or get people in to manage it fully for you. You take a share of the revenues. Spreading yourself too thin doesn't work.