The Consumer Credit Card drives ecommerce

The customer for ecommerce consumer products will usually be the family 
spouse acting as the only the person responsible for making the purchase 
by credit card. 

Companies that offer the same products as you in the same ecommerce 
marketplace generate direct competition, and this should be the easiest 
for you to evaluate and counter.

If the price becomes significant or if the item will be used by other 
people then it is likely that other people will be involved in the purchase. 

Work out if it is easier to analyse the consumer base by size or by product 
bought - maybe by frequency of use or purchase? 

Who exactly uses this product and who decided on a credit card transaction? 

Can you group the customer by professional category or by age or gender or 
geographical area?

Can you describe the customer by behaviour or attitude or lifestyle?

To establish indirect ecommerce competition you will need to look at 
companies that may pose a threat if they can easily diversify into your 
market, even though at the moment they may offer the consumer different 
products to you and in other markets.