1. Free Shipping
Orders of at least $550 receive free ground shipping in the US, although not all products are eligible (and those that aren't say so in their product descriptions).
2. Flat Rate Shipping for Bulk Orders
Orders of at least $150 receive flat rate shipping of $5.99 with the same qualifications and therefore need to pay attention to product descriptions as the first tip.
3. Connect on Social Media
Like PetEdge on Facebook for coupon codes and alerts about sales, deals, and promotions. The best part is unlike many other businesses' Facebook pages, this one is primarily posts about ways to save with very little else.