You can integrate several websites using the same account! 

Basically how this works is that a separate xpub (extended public key) is needed for each website. This way each website funds go to a seprate wallet and you can easily identify the website you received payment from. Please follow the below procedure

  1. Get a new xpub. How to get multiple xpub's from same wallet?

    Many wallet apps you can create multiple wallets within the same app or account, each offering their own xpub. Airbitz and Copay are two wallet apps that can do this easily on mobile devices (Copay also on desktop). You can install these alongside your existing wallet app if needed.In Wallet you create a new wallet from Settings > Wallets and Addresses

  2. Add this new xpub to Wallet Watcher
    Go to Wallet Watcher > Address Watcher. Click New Address to paste in your new xpub, then click Add.
    You can add a tag to make it easier to identify later
  3. Set callbacks for each of the websites
    You can go to Merchants > Settings and assign a callback URL for each xpub in your Wallet Watcher account. Just select each one from the dropdown box.

    Setting callbacks for different xpubs

  4. APIKey Both the websites will use the same APIKey. There is no need for a new API key. You can view your APIKey on Merchants Page

Merchants Page