Below are some plumbing-specific promo items and then some items that we would do if we owned a plumbing company with an explanation why. The blue text should all be clickable links, please let us know if we spark any ideas.
Plumber Stress Relievers
Toilet Stress Relievers
Pocket Tools - no one throws away a tool, super long marketing shelf life
Tape Measures - same as with tools. Have you ever seen anyone throw out a tape measure?
Other magnets- we sell magnets with every pro sports team schedule and your logo prominently printed. Anyone with even a remoteinterest in sports is going to leave that up all season. There's nothing more annoying than having to constantly Google when the next game is on.
The mug you picked was a good idea because unless the recipient breaks it, ceramic mugs have a super high shelf life. I can't remember the last time I threw away a mug. Mugs with cool graphics or interesting handles tend to become favorites.
I usually recommend when someone orders a high end mug to also do a lower end item like a plastic stadium cup because people tend to collect those as well and keep them for a very long time. Stadium cups have a long marketing shelf life and make great home show giveaways and can also function as a great plumber "leave behind" gift. Cool freebies, no matter how low cost, are absolute friend-makers.
Note: Most of our stadium cups are under $0.50 each and are USA made, BPA free, and top rack dishwasher safe.
Tote bags are another item that are super low cost, have a HUGE logo print area, and can be given away at conventions or used as plumber leave behinds. It's also kind of cool to see someone using your tote at the local grocery store as a reusable grocery bag.
T-shirts - Right now we are running a deal for size S-XL Gildan 5000 light colors with a one color front one color back print $5.99 each at 108 pieces quantity with no setup charges and free shipping to anywhere in the continental USA.
Pens - yes, everyone sells pens. But we sell a ton of American made promotional pens that are the same price and write just as well as the imports so we tend to promote those and people like them. I gave you the direct link to that warehouse, we're a registered rep of Cameo line so anything you like on that site we can do as well.
Our favorite item from them is the recycled US Currency pen, we've done them for a pawn shop before and they were a huge hit, but you could do a promo telling people to stop flushing their money down the toilet or something like that.