Depends on your site and the content on your site. We use the mix option. We find it that it works for our site. We have done a test and run of running only affiliate vs only adsense, and we found that the results are very similar to when running it mixed. There was a slight increase in generated rev when running both. Good luck
The answer to this cannot be universal. Because what you need to put depends on what niche you are in. For affiliate marketing to work, you need to choose a micro-niche which has very little competition. But if you pick this niche, the targeted adsense inventory will also be low and hence the money you earn per click will be low..doesn't make sense to put in an adsense here.. But if your niche is broad, then affiliate marketing will not click well enough, but you have enough ad-inventory,so adsense works perfect here..
If it is an information rich site that caters to a narrow niche, then I would go with a mixture of the following: 1. Pay Per Lead - In some niches like weight loss/debt help you can get between $10 and $100 per lead when your site visitors perform a certain action (eg request a free debt help quote or a trial of diet weight loss pill etc). PPL in my experience is far more potent than Adsense. You can find a free list of some of the best pay per lead program niches here: http://www.nichebusinessempire.com/backdoorcomp.htm 2. Use the best affiliate programs - Not just the highest paying ones, but the most popular and well reputed products. And, if possible use residual income programs where you get a monthly pay check. Residual income programs is not something many people look for when creating their sites and that makes no sense - you do the same amount of marketing, so why not be paid every month for that effort instead of just once. 3. Adsense - in niches with financial muscle, Adsense is still a worthwhile option. You really need to understand the niche you're in and use the ad space accordingly. If you're in a poor niche with few paying prospects and with products/services that sell for peanuts, you're just in the wrong business I'm afraid, and that's probably what's causing the poor earnings.
Every situation is different, so why not do a test? Google doesn't require a minimum number of impressions or a long-term commitment, so you can pull the adsense code from your pages if you aren't happy with the results.
Using adsense and affiliate marketing both work , however make sure for adsense you have decent content and a well laid out site, if not you are just essentially trowing your money away.