In short, the gravity score is a method of figuring out how many affiliates are promoting a particular product – no more, no less.  In other words, it’s an indicator of competition from other webmasters promoting the product. 

It’s a little confusing as to how the gravity score is calculated.  CB Graph has a great article about gravity here.  I’ll give you a quick excerpt from that article:

• Gravity is recalculated everyday;
• It is a sum of scores received by individual affiliates who sold at least one copy of the product for last 8 weeks;
• Each affiliate may add at most “1″ to the product’s gravity;
• Each affiliate adds to the today’s gravity:
  • “1″: if he/she sold at least one copy of this product yesterday;
  • “0,96″: if last affiliate’s sale was 2 days ago;
  • 3 days ago: 0,96^2 = 0,9216;
  • 4 days ago: 0,96^3 = 0,884736;
  • n days ago: 0,96^(n-1) (n is not deeper than 8 weeks)

As an example let’s consider a product which is being promoted by two affiliates. We know that first affiliate had sold 3 copies of this product yesterday and 7 copies 2 days ago, but second affiliate had sold only one copy of the product 2 days ago. So, to find today’s value of the gravity we have to add affiliates’ scores. The first affiliate adds “1″ (because he sold at least one copy of the product yesterday) and another affiliate adds only “0,96″ (his last sale was 2 days ago). And the Gravity = 1 + 0,96 = 1,96.

So what does the gravity score mean to you?

Unless you are the product owner, it means very little.  If you are considering promoting a product, the only thing you need to know about the gravity score is that it means you will be competing against a lot of other people who are also promoting that product.

Many people believe that if a lot of people are promoting a particular product, it must be because it converts.  After all, people wouldn’t be promoting a product if the conversions suck, right?  Nope.  Sadly, a lot of people don’t even realize what a good conversion rate would be, so they mistakenly think a product is converting just fine, when it may not be.  Plus, a lot of people promote a product simply because they like the graphics, or they like the name, or because they’re buddies with the creator.  So essentially, gravity means very little.

I actually get most of my sales from the products that have a lower gravity.  I’m not sure why.  Maybe it’s competition, or maybe it’s because I have a knack for choosing products that will convert.  Who knows?  But don’t choose to promote a product based solely on gravity.  There are a lot of GREAT products out there with little or NO gravity!