I also agree with the majority here as well.. But I would probably start out as follows: Start with something your familiar with or that your an expert about first. What are you an expert at? What do you do for a living? It will be easier for you to choose keywords, write articles (for article marketing), create blogs, etc because you are already familiar with that field. But first you should be making sure that there is a market for which ever field your considering... The more people searching the more likely you are to make sales... If that fails you should then probably search by gravity, reffered, as well as the trends.
After doing some keyword research, I choose by gravity that is not less than 50. I also do Google search on "Product name + Forum post" to see what people are saying about selected product before finally deciding which one among them to promote in that niche.
What about popularity, if the product is popular, it means that people are promoting it and people are buying it. Also what happens if the gravity is high and falling like a ton of bricks, would you want to be promoting this product. How about refunds, should you not check the % earn and total earn to see if there is a difference, and if there is it may be that the product is getting a very high refund rate.
I'd rather look at conversion rate... oh wait... it isn't published.... which brings me to: CONTACT THE VENDOR - and ask for conversion stats, and just to ask for advice, materials, ask questions generally... I wouldn't dream of promoting something I didn't have access to the owner on, if I didn't know it was good quality, if the vendor hadn't done his split testing and hard work in testing / proving his product sells.. especially if I haddn't seen any proof of conversion or refund rate. Some vendors won't reply to you, but use this as a test - if they won't reply then you are either too smalltime for them and unimportant, or they just have too much on, but either way I would take that to mean try approaching someone else - if they are responsive, honest, and helpful to you then they probably believe in their business, it probably does convert ok, and they probably spend time to update it, answer buyer questions, try to prevent refunds etc etc.
Choose products which you feel like buying and that looks sensible/people might buy. Then visit the sales page is it good if so look for the affiliate tools or resources and if everything is done for you ready made thats a good choice of product.
You can't pick a product a say you've got a winner straight away unless you get to know the target audience first. Drive lets say 1000 - 2000 hits to your landing pages and only then you can say that the product either converts or not. Karismapie - Definitely there are products with a low gravity/ thus a low competition that can turn high conversions but that's not the only ingredient to pick your product - you need to test it yourself
I tend to find the market first and then go for a product that is suitable.. I think that way is more effective because then you know you will already have buyers waiting.
Gravity also means a MILLION affiliates must promote it. Meaning PPC keyword bids are competitive. Best to find a product in demand that's not too popular yet but on the rise. try http://www.emailtracer.com/affiliates/ it's not huge yet but easy to promote.
You can choose products by popularity or Gravity, these are the only two relevant searches I use as mentioned on my guide at: http://www.bestblogs.asia/does-clickbank-work.php
becareful Rippa, My friend was using the same strategy and google has banned his account as he point it directly to the landing page.