Hold on to it for a moment and don't rush into anything. There are so many things out there that work. So many ways to increase your income. If I were you, I might start looking at having some type of software created that automates a function that marketers do all the time. We are always hungry for a piece of software that makes life easier. I'd look for a need and then hire a programmer to fill it. Just something to think about...
Best suggestion, this could be the wiser investment, buy out a website which is making good money every month from affiliates or adsense (i would personally prefer adsense as it is much more stable and easy to maintain, just needs content and promotion), though the returns might only be 1/10th or so of your investment every month, but this will be the safer bet.
Well is certainly doesn't hurt to brainstorm with others, but I have a feeling that you will probably come up with great ideas all on your own. You have done very well for yourself, so don't sell yourself short now! You might want to consider a content site. I have my own writing business, but other writers rely on getting their work from places like Textbroker, Ecopywriters, etc. If you had a site stocked with independent writers, you could charge marketers $15 for the articles and pay the writers $8 - $10. Just a thought!
You can give it to me *joke* Seriously though, If I had $10k I would go to flippa and find a good website to buy. Do lots of research before buying a site...etc.
Flippa is the best option dude.. Dont take risk buying for some $5000 or $2000.. if you try bit you can get a High pr website at a cheaper rate, if its theme is not good, better change its theme , make sure it looks good with good content , then sell it for other good price.. better start with one domain, if it works you get some exp, then go ahead with some 2 or 3 domains, rinse and repeat... (Its not too risky as well, may be bit time taken..) if you still dont like any other advises, Pm me , i will send you my bank details, you can transfer it to me... Have a gr8 day!
keep trying to learn new things. don't just stick to one money making idea. you gotta have more than one source of income just in case one day, something doesn't work. you have an option you can relay on
You could create around 300 to 400 micro niche sites with $10k, do them in banches of 100 they'll cost you like 20-30 dollars a piece to set up and rank but 300-400 good niche sites you should be looking at getting on average a $1 a day per site.
Personally I would invest that money into advertising affiliate offers via PPC. $10,000 is actually quite the amount, you can even develop your own product and sell it online with that budget. Or you can start an eccommerce store and use the money for inventory and marketing. A lot of options to consider, I suggest doing research and putting thought to what is best for you.
I'd definitely think of something new and unique! Create a real quality, interesting website that can grow. Invest the money in promotion and advertising.
You could have a look at Fiverr and see what is selling, but in the long term with that amount to invest, I would run PPC campaigns on some affiliate products, and based on performance create sites targetting those keywords, rinse and repeat