Investing in Index Funds – I use Vanguard for this, but there are several reputable sites out there that allow you to do the same thing. It’s a good way to invest excess cash that you don’t need now and use it to diversify your portfolio. I’m not going to make a specific recommendation here, but Vanguard does have a page that will make a recommendation to you based on your risk tolerance. This is generally going to require more up-front money than Lending Club (probably $1,000+), but if you have the money, it’s something to consider.
Connecting two entities is another great way to make extra money by spending less energy. So can always have an agreement with some business entity to give clients on referral basis and earn a commission. I recently hired a designer for some work and I asked him if he knows someone who can PRINT the designs for me. He referred me to his friend who done the printing work. I am sure he must have got some cut for the referral and there is nothing wrong in it. Its a smart way of earning money.
One of the easiest ways to increase your passive income is to shift your savings to a bank that pays a higher yield on your savings — for example, Discover Bank and EverBank pay almost 1% for your money. Although it doesn’t sound like much (especially in this low interest environment), little things do add up and eventually interest rates will rise.
If you want to really start tracking your finances, and I mean not just your spending but your investing (that's where wealth is built), give Personal Capital a look. They will give you a $20 Amazon gift card if you link up an investment account that has $1,000+. No strings. It's a cornerstone of my financial system and I think you owe yourself a look. 100% free too.
There are a couple of problems with direct investment in real estate though. It’s expensive to buy even a single property, a minimum of tens of thousands of dollars, and there’s no way most investors can build a portfolio of different property types and in different regions to protect from those risks when you have all your money in just one or two investments.
In 2012, even I wrote a 150-page eBook about severance package negotiations that still regularly sells about ~35 copies a month at $85 each (2nd edition for 2017) without any effort. In order to generate $2,975 a month or $35,700 a year in passive income as I do now, I would need to invest $892,500 in something that generates a 4% yield! To earn $10,000 a year in passive income would therefore need roughly $250,000 in capital.
An obvious example is over exposure to bank stocks, which have been excellent investments for over a century. Though a foundation of most portfolios, bank stocks do involve more risk at certain stages of the economic cycle than many realise. Being less exposed to bank shares in the last few months could have preserved some capital. So, a more diversified approach can help mitigate some of these risks.