Just like everyone should be split testing, they should also be running their best campaigns on different networks and traffic sources as well. A great example of this would be if you were running an offer on Google Adwords that’s been profitable for quite a while. Since you already know which keywords and landing pages are working best, it wouldn’t be hard for you to take all of that same information and create a new PPC campaign through Bing.
I personally prefer to do it that way--you can create a more convincing review that's more likely to make sales. It's not always possible or practical, though; for example, would you break up with your significant other just to test a product for getting your ex back? ;-) In cases like that, or if the product is expensive, it's usually best just to use the vendor's affiliate resources instead.
You can sell affiliate stuff if you did not use the stuff but a high, high, high, really high level of clarity is required to do this. Most bloggers lack this clarity. I recall Tony Robbins selling/being an affiliate for a $25K coaching class. Never took it. Never sat in it. But the guy made millions. He had full clarity in selling without seeing. So he rocked out the selling.
I would have one partner create a separate page/contact form specifically for the advertiser – so only people who see that contact form are people who were referred to by the advertiser. The advertiser would use that page as their outbound link. I know you can track outbound clicks in Google Analytics events and Contact Form conversions (usually through most contact form plugins) but that is the best way I think. Never done it, but this is how I see most affiliate programs like that work.
When you’re looking for affiliate programs to promote, you’ll want to choose ones that pay out a good commission fee. When I first started out, I started promoting products that I really liked and that my audience liked, but they only paid out 10 percent of the total sales. Well, figure the average order size was $65.00, this means that I only made $6.50 per sale. It would take a lot of orders for this to amount to anything substantial. So depending on what your audience’s comfort zone is in relation to price point, you’ll either need to promote products that have a high price point, or that offer a high commission rate. Do your homework and search around – there are tons of affiliate programs out there. I personally like working with companies that pay per lead.
DOI – Double Opt-In. These offers require more than one action from the user. Originally, this concept required users to enter their email address and then click a confirmation link in the “welcome” email. These days there can be more requirements, like filling out a profile, defining interests or uploading a photo. DOI provides better list protection, communication with subscribers and user relevancy than SOI.
As you become comfortable with the affiliate marketing process, you can consider both specialized (e.g. fly fishing) and broad (e.g. weight loss) niches. Don’t forget to track your marketing metrics! They are usually provided by your merchant and/or affiliate network. This way you'll be able to know which products your audience are responding to and which ones aren't generating any profits for your business. This is especially important if you are investing into paid advertising to drive traffic and promote products as an affiliate...
The best way to find suitable brands to promote is by simply using a search engine using: '[Brand] + Affiliate Program'. Some companies run in-house affiliate programs however, this is a very specialist area. Therefore, most companies opt to employ an 'affiliate network' which has already built a large base of affiliates and gained years of experience in running successful programs for clients.
For example, if I talk about how cool a product is, and then you find out that I’m an affiliate for them, wouldn’t you as a conscientious observer become skeptical as to whether my information is biased, if perhaps I’m only saying how cool something is because I can get paid for it? Wouldn’t that make you question my integrity with other things I say as well?