I’ve been lucky enough to make my living totally online since 2007. One of my primary income streams involves promoting affiliate products by placing free ads on sites like Craigslist and backpage. If you want to make money posting ads on sites like these, following are answers to four questions I’m asked frequently about backpage, my favorite “go to” free classified ad site.FYI, the advice dispensed here works no matter which free classified ads site you use.Answers to 4 Common Questions about Placing Free Ads on Backpage1. Which Cities to Place Ads In: Backpage gets a lot of traffic. How much? According to TrafficEstimate, a site that estimates the amount of traffic a website receives on a monthly, annual, etc. basis, during the month of January (2013), the site received 20,394,000 visitors.There are close to 400 cities you can place ads in, but a handful of these get the bulk of the traffic. Following are the top 20 – based on traffic — to place ads in on backpage to make money online quick.Backpage Cities: The Best Ones to Place Free Ads InAtlanta, GABoston, MAChicago, ILDallas/Ft. Worth, TXDenver, COHouston, TXLas Vegas, NVLos Angeles, CAMiami, FLMinneapolis, MNNew York City, NYPhiladelphia, PAPhoenix, AZSan Diego, CASan Francisco, CASeattle, WASt. Louis, MOTampa, FLToronto, ONWashington, DC2. Categories to Place Free Ads In: One of the most popular categories to place ads in is “Biz Opps.” This, the “Business Opportunities” section, is where many of the affiliate opportunities you’ll likely be interested in promoting will properly fit. “Money-making” opportunities happen to be the most popular type of affiliate products to promote to make money online quick.A note about categories: Be sure to follow site guidelines. For example, some marketers will post business opportunities in the “Jobs” section. The last thing someone who’s looking for a job needs is to run across an ad featuring a “pay for” business opportunity.You pay for opportunities; you apply for jobs; note this difference. And, don’t abuse the site by posting in the wrong category – even if you feel that you can get away with it. It’s just unethical.3. How Often to Place Ads to Make Money Consistently: At the beginning of my affiliate marketing career, I placed ads daily, which I think every newbie should do in order to start making money consistently (eg, weekly, then daily).FYI, also employ other methods, eg, article marketing. If affiliate marketing is something you want to eventually grow into a full-time income, it’s likely going to take a few combined online marketing methods to earn enough to make this a reality.4. How to Select Products and/or Services That Will Sell: As a self-publisher, I mostly promote my own ebooks, among a few “evergreen” affiliate products.The most important piece of advice I can give on how to select products that will make you money is to go with those you’re passionate about and/or have experience with. The reason is, it’s much easier to “believably” promote things that you really like and/or have experience with.There’s a lot of garbage online and potential buyers can sense phoniness. So just don’t go down that road. To make money posting ads, there are thousands of products you can choose from on affiliate marketing sites like CommissionJunction and Clickbank. So, build your internet marketing career around some good ones you believe in.And FYI, it’s free to sign up with most affiliate programs, so it costs you zero dollars to get started.Why It’s Never Been Easier to Make Money Online QuickThe internet and free classified ad sites is a match made in marketing heaven, making it easier than ever to make money online from home – quick.