You must understand that Affiliate Egg parsers websites directly and check the structure of the site. Sometimes an original site can change a design, so you will need to fix a parser. We give a guarantee on custom parsers during 6 month. In this period we will make update of your parser for free. It is good that most of shops uses the special schema structure which is always the same, even if they change a design, so you will not need any fixes.
You can create your custom parser. You need to have php and xpath skills for this.
All custom parsers must be inside folder: wp-content\affegg-parsers
An example of the parser you can find in the folder