For those of you who don't know what an FFA site is, it's basically a website where you can post a link/add to your website for free. Generally it is also posted to many other sites at the same time and hopefully somebody sees your link...free advertising in other words. This also creates backlinks to your website. When you post a link, you are also giving permission (whether you know it or not) to receive confirmation e-mails back from the site owner.
What seems to happen though is many people see this as free advertising and get angry when, not only do they not see a flood of sales come pouring in, but they start receiving other people's offers. I know when the first time it happened to me, I couldn't figure out what was going on and was frustrated at the results.
Let's back up a moment and look at the bigger picture of what an FFA site is and its TRUE purpose. The true purpose of an FFA site is for the owner of that site to promote his/her business. It's really not just because he's a nice guy giving people a free advertising place.
(If it were such a goldmine for pulling in sales, he would be doing it himself). That is just the bait, getting people to his site to post their links, thinking they are getting free advertising, so he can respond with "confirmation" of your link, and his business ad.
Those confirmation e-mails are NOT spam. You had to agree to receive them in order to post your link. Who are reading these ads anyway? So is posting to FFA's a total waste of time? Not necessarily, you do get an occasional sale, people do go back to post their links and sometimes take a quick look through the links to see what's there while they're at it.
So what's the answer? Get your own FFA site to promote your business. There are many excellent resources out there. I have found from personal experience however,that many of the services offering FFA's sites, offer a free version or a paid upgrade. The phrase "You get what you pay for" comes to mind with these. I've used several kinds and found that the paid upgrades more than paid for themselves in sales. Shop around however to compare between companies.
You can promote any product through this method; information products, crafts, vitamins, whatever. You could have the very best on the entire internet, but if nobody sees your offer, it's not going to get the sales you desire. It takes traffic to get sales. These sites are options for driving those numbers to your site. Free classified ads sites are also in this same category with the same purpose and can be worth pursuing.