One of the best ways to build wealth is to get a handle on your finances by signing up with Personal Capital. They are a free online platform which aggregates all your financial accounts on their Dashboard so you can see where you can optimize. Before Personal Capital, I had to log into eight different systems to track 28 different accounts (brokerage, multiple banks, 401K, etc) to track my finances. Now, I can just log into Personal Capital to see how my stock accounts are doing, how my net worth is progressing, and where my spending is going.
While compiling this list, I did my best to avoid scams, and stick with practical ideas that work. I have tried many (but not all) of these ideas. Some of these helped me earned a few dollars here and there, but there are some that helped me earn extra money on the side every single day — and some are still providing me with revenue! Note that not all ideas will fit your skills and abilities. What works for you depends on your abilities and your current financial situation.
As for me, I started focusing on passive income last year, but have owned rentals for 5 years. $25k now outside retirement accounts in mostly real estate. Looking to invest another $500k cash into real estate to get about $65k, and then 1031 under performers next year to hopefully boost that a bit higher. Heavy in real estate, but feels lower risk than the stock market to me if you have cashflowing properties. Real estate is inflation adjusted, and built in cashflow raise when the loan pays off.
To save time and effort, a person can group two or more of their passive activities into one larger activity, provided they form an "appropriate economic unit." When a taxpayer does this, instead of having to provide material participation in multiple activities, they only have to provide it for the activity as a whole. In addition, if a person includes multiple activities into one group and has to dispose of one of those activities, they’ve only done away with part of a larger activity as opposed to all of a smaller one. 
When most people think of investing opportunities, they think of stocks, bonds, and precious metals. While these are still some of the most common ways to invest, the platforms have evolved, and there are more options than ever. Gone are the days of mountains of paperwork, high brokerage fees and unattainable account minimums. Now you can invest on your own terms.
After these tenants move out, I'm thinking of just keeping the rental empty with furniture. It sounds stupid to give up $4,200 a month, but I really hate dealing with the homeowner association, move-in/move-out rules, and maintenance issues. Given that the condo doesn't have a mortgage and I have to pay taxes on some of the rental income, I'm not giving up that much. The condo can be a place for my sister, parents, or in-laws to crash when they want to stay in SF for longer than a week or two.

Endorsements are a form of advertising that uses famous personalities or celebrities who command a high degree of recognition, trust, respect or awareness amongst the people. Such people advertise for a product lending their names or images to promote a product or service. Advertisers and clients hope such approval, or endorsement by a celebrity, will influence buyers favourably. For example, Sach

The term Marketing comes from the words ‘market’ and ‘getting’; conquering the market. The term marketing has been around for over a 100 years. Today, it’s still about large companies wanting to conquer the market, gain market share and (new) customers. Marketing methods are comprehensive and Viral Marketing is a relatively new way. This technique increases the awareness and reach of a product or brand by using social media. It’s word-of-mouth advertising using the internet. The more people who know about it, the better. Each company that uses a marketing communication goal to express a specific marketing message can do so by publishing digital video clips, for instance. These days, commercial organisations employ viral marketing to generate brand recognition, launch a new product or draw attention.
I just graduated college in May and was fortunate enough to secure an entry level consulting position that pays 55k/yr (a little less than ~35k after 401K, other benefits, and the lovely taxes that government bestows upon us). I started from “scratch” with my finances and have ~$2.3k in an online savings account. Since starting work a couple of weeks ago, I’ve had an aggressive savings plan (saving around ~40-50% of my monthly income). However, I’m going to become even more aggressive and live off 1 paycheck a month (and save the other paycheck) like you have suggested in many of your blog posts.
When you write a blog post on your website, that article immediately goes out to your followers. But the content also remains on the website for others to find via search engines or social media. Each time somebody reads your content, there’s the potential to serve them an ad, product for purchase, or affiliate link (many links in this post are affiliate links). Each set of eyeballs that read your content carry the potential for passive income.
The ultimate goal of marketers interested in creating successful viral marketing programs is to create viral messages that appeal to individuals with high social networking potential (SNP) and that have a high probability of being presented and spread by these individuals and their competitors in their communications with others in a short period of time.[9]