In a world of limited resources, you should leverage and maximize existing marketing "working capital" to carry your messages. There’s a disproportionate amount of investment to start a new program, campaign or initiative than to add something onto an existing campaign.
The idea of piggybacking is to look at any marketing program and piggyback on it with another marketing message. Or, alternatively, piggyback every marketing vehicle to reinforce your main message (example: logos on delivery vehicles, URLs on receipts, etc.).
Think about all of your customer touch points and ask yourself, what else could be added that wouldn’t take away from the primary message.
Can you add a cross-sell to a landing page that may entice a visitor to think of buying something else before they leave.
Can you add something to what you ship the customer?
Can you add a message onto your voicemail?
Can you add a message from your customer service, sales or support representatives?
Do you (moderately) leverage links from one page to another page in your site (The Resolving Door concept).
The IDEA and PRINCIPLE of Piggyback is to look at any and all activities and consider how it can be added to and leveraged and maximize its full potential…but not past the point it becoming overwhelmed, cluttered, or diluted.