If you add up all the services you get, the premium membership is a steal. For example, you’ll notice they include unlimited keyword research with a membership. Other paid keyword research tools sell for $49 or more just by themselves. Add in website hosting, and there’s another $10 / mo. Add on the website security package, and there’s another $10 per month (I’ve paid as much as $29 / mo just for website security). Just based on those things alone, Wealthy Affiliate is a great deal with all of the resources and tools you need in one convenient place. Not to mention all of the training, tutorials, and support that is included with the membership.
But don't make the mistake of thinking this will be a passive source of income—you're on call whenever you have a guest and you'll always need to keep the place clean for incoming visitors. On top of just renting on Airbnb, consider offering your guests paid add-ons, like Lauren Gheysens', Royal Day Out in London, England—where she gives visitors a local's only tour of the city, complete with bespoke 18th century costumes.
Affiliate marketing is also called "performance marketing", in reference to how sales employees are typically being compensated. Such employees are typically paid a commission for each sale they close, and sometimes are paid performance incentives for exceeding objectives. Affiliates are not employed by the advertiser whose products or services they promote, but the compensation models applied to affiliate marketing are very similar to the ones used for people in the advertisers' internal sales department.
Hold a yard sale. If you have a yard or garage and plenty of items to sell, you can have a yard sale as early as tomorrow. By advertising your sale on local Facebook pages and Craigslist, you can also skip the paid newspaper ad and keep all of the profits for yourself. If you don’t have time to price everything, try asking patrons to “make an offer” or grouping similar items on tables with an advertised price (e.g. everything on this table is $5).