Simple, put in some more money into advertising with google adwords. After that post in relevant forums with your websites in the signature, this will increase your backlinks, and you'll soon be getting valuable search engine traffic.
To advertise an MLM website is very easy.Just join some free traffic rotating websites.You would get traffic to your sites.But to get genuine and unique visitors, you need to join a recently lunched site trekpay.You have to put some money to advertise on it.Most of the members in trekpay.com are genuine and has the capacity to pay.This option is better than Google adwords.Just go and have a try.You would find it profitable.Even your forex trading sites would receive decent traffic.
Yeah JBs suggestion beats mine, but I'd recommend that only for your MLM site, because you'll be targeting the correct people. But since you haven't mentioned a niche for your other two sites, I mentioned adwords.
If you have the money then you could just buy some Adwords traffic. Now, don’t worry if you don’t have the money to advertise your site, you can still get some free traffic to your site by doing some SEO. It might be a long time but it could get you the desired traffic which will avail of your affiliate program.
If you can’t wait that long then you could settle with article marketing.