Running a coupons website can be very lucrative. Find a coupon niche, select a WordPress coupon theme, and then display relevant coupons on your site. When your audience uses the coupon codes or discount links, you will earn an affiliate cut, for example, you could set-up a site dedicated to iHerb Coupons or add a page to your website with Web Hosting Promo Codes. Coupon websites are quite high maintenance as they need to be constantly updated with new offers. However, if you build up an engaged audience and allow them to post coupons and discounts they have found themselves, then quite quickly your workload will reduce.
The peer-to-peer concept is coming to virtually every corner of human existence. That includes the hospitality industry. Through AirBnB you can actually rent out your house for various lengths of time for a predetermined fee. That gives you an extra income on your house and gives the visitor the benefit of having an entire house, rather than being crammed into a single hotel room.
Since time is the most precious commodity on this earth, invest the time at the front-end so that you can reap the benefits on the back-end. This means putting in a bit of sweat equity and not getting paid today. Rather, you'll get paid somewhere down the road. And you'll continue getting paid whether you keep building that passive income stream or you stop. It's obvious that this is the preferred route, but clearly the road less traveled.