I see this question posed a lot online regarding Forex CFD companies of which many have high paying affiliate programs. This has led to some to claim that companies which offer such high paying programs must be somewhat dodgy as it would take a long time to make back the money paid by the affiliate advertiser. This seems understandable as it appears to seem that in order to have a profitable business model the company would have to be making hundreds of dollars from each new customer they have recruited from affiliate marketing schemes in order to remain profitable. 

The Costs of Affiliate vs Standard Internet Marketing 
What a lot of analysis misses is the high cost of standard internet marketing through providers such as Google Adsense etc. A click on an advert may cost the publisher of that Ad anywhere from $0.65 to $2.20 for an advert in the relevant financial services niches. I have heard that most online click through ads have a conversion rate of around 2%, which would lead to me estimating that for each new customer acquired through such online advertising would cost a Forex CFD provider between $32.50 up to around $110. Which seems to be a lot less than many of the online affiliate schemes pay. 

However, affiliate schemes often require more than just a successful sign up. For example the affiliate scheme at the FSA regulated Plus500, offers up to 500 dollars for attracting an individual from the United Kingdom. But the individual must place a qualifying amount of trades with a real money account so many of the customers who do sign up through an affiliate advertiser may not in fact make that advertiser any money.  

A lot of schemes offer an option between CPA (amount per signup) and revenue share. Revenue share simply gives an affiliate advertiser a share of the revenue made from the clients signed up through their advertising. While this minimizes the amount of income made by the provider it seems to be a much more sustainable option, however theoretically the advertiser could make far greater revenue if he signed up customers that stayed with the company for a very long time making the company a large amount of revenue. 

So in summary the financial services industry is highly competitive industry where obtaining customers can cost a lot. So in fact affiliate marketing schemes may not be as cost ineffective as many people seem to believe. 

Why a company might not opt to have a affiliate scheme? 
In Europe MiFID regulation attempts to ensure that consumers get full consumer protection and part of this involves protecting individuals from false claims. For example in 2010 easyforex received a 10,000 euro fine for not properly presenting the risks that Forex trading involves. Opening up an affiliate scheme with a good rewards program has the potential to get you into deep waters with a regulator as affiliates might sell the benefits of the product and trading without emphasizing the high levels of risk that Forex trading necessarily involves. 

Most regulated providers try and protect against this by having a big disclaimer and clearly emphasis the fact that individuals will be removed from the affiliate program and have their earnings taken away if they do not properly emphasis the risks. However many unregulated outfits make no such requirements meaning that individuals can push the product without regard for properly presenting the risks and rewards.  

Should a company having an affiliate scheme put me off? 
I would say Yes and No, many of the best providers have no need for affiliate schemes as the quality of their service and word of mouth is all that is needed to drive new clients to their company. Or alternatively they adopt highly targeted marketing programs aimed at attracting customers. 

But all that being said there are many well regulated and respectable companies that in fact do have affiliate schemes. I would thoroughly research any company I considered depositing whether or not they had an affiliate scheme.