If you already have an account as a standard user just click the Retail Portal button and follow the instructions to create a mechant account.
If you are new to Whatsinstore click the Merchant Login button and follow the instructions on screen.
To add an offer go to the Retail portal and click on 'Offer".
Click on the 'Add New Offer' tab in the left column.
Start typing the name of your product in the Search product dialogue box.
If your product is not listed click the "Create a new product listing' link and follow the process.
For a video run-through click here How do I add an offer