Here are some fun ways to include the stickers:
Bridal Showers/Engagement Parties
Include in fun games, such as if anyone uses the word "wedding", take their sticker. The winner will be covered in stickers. Don't forget to seal the prizes with a sticker.
Add to any favor for a personalized touch or apply stickers to centerpiece vases. Decorate a toiletry basket and display in the reception's bathroom facilities. Have your servers wear in coordination with their name tag. Having a candy buffet? Attach to the candy bags.
Invitations / Save-the-Dates
Many stickers are small enough to use as a seal for the invitation's envelope. Enclose a sticker (with covered backing) for guests to stick on calendar to mark the date.
Gifts for Bridal Party / Guests
Having out of town guests? Consider a special basket or bag complete with essentials for guests to receive when they arrive at their hotel. Attach sticker to complete packaging.