If you want to collect users’ mails for further actions or make them reach any product page you may set goals. You can go with no goal settings either.
Create memorable campaign name that you can distinguish later
There are 4 types of goal:
Destination to make sure that user or lead visited exact product page. There is a product that you want to put in priority, good then. Just leave a link to this product in the pop-up. Name it and put the conversion value you expect to earn during the campaign.
Funnel to guarantee that user visit the page you want through another one. Build the funnel from different popups in order to ensure that the user reaches a specific product.
Collect data to collect leads/users’ emails;
Comeback to call your potential customers to action and take a look at your products again. Make one of the pop-ups to appear in front of the client before he decides to leave your site. Try to get his attention with an undeniable offer;
It's optional and it shows profit you expect to receive from campaign
Has many values from subscribing to emails from you to donations which user can leave. Depends of course on your desire and meaning you put into your webstore.