Send it (A Promo Product, That is) in a Letter

Snail mail might seem old-fashioned to the young and tech-y, but businesses still send a lot of letters. Contracts, invoices, checks, and other correspondence go the old-fashioned way.

One way to add value to those letters is to include a promotional product - something useful the recipient can keep, and something that will remind them of your company.

Now, some promo products won't work for this purpose. Good luck cramming a squeezy foam stress toy into a #10 envelope. But there are lots of options that can slide right in with your invoice without being too much trouble.

Look for items that are flat (no more than  ¼" thick) and that measure 3" by 8" or smaller. They should also be as light as possible. Most likely, you'll have to add an extra stamp or two when including a promo product in a letter.

The standard rate for a first-class letter, $0.44 as of this blog post, will cover a 1 oz. letter that bends easily. Add something firm enough that they can't run it through the machine, and that's an extra $0.20. Add another ounce, and that's another $0.20 too.

Check the weight of the item and include additional postage in your budget.

So what kind of promotional items work well in an ordinary envelope? Here are a few of our suggestions:

Monitor Stick-Its One of the cleverest products we saw in 2011, the Monitor Stick-It puts your logo right where they'll see it all the time. The little white card includes small sticky notes and flags, and adheres to a computer monitor for easy accessibility. Doubles as a bookmark, too, as long as you leave the adhesive on the back covered up. $1.59 each with a 1-color imprint, $55 setup, minimum order quantity 200.

KlipNotes This is another item that sticks onto the frame of a computer monitor. It doesn't look like much, but it's a multipurpose dynamo. It can hold photographs, business cards, reminder notes, and any other piece of paper right at eye-level, effectively turning a monitor into a memo board. Our monitors here at Gorilla HQ are absolutely covered with these things. When you send them, consider sticking the piece of mail in it so the recipient instantly understands what the item is all about.$0.99 each with a 1-color imprint, $50 setup, minimum order quantity 250.

Mints in a Credit Card Case It's nice to carry mints with you in a pocket, purse, briefcase, or backpack, and the latest trend is packaging that's as small as a business card and nearly as thin. The micro-mints inside are just enough for a breath-freshening boost. Around $1.00 each with a 4-color process label, $60 setup, minimum order quantity 250.

Dog Tag Keychain Whether your key chain is small and light or resembles a junior high janitor's, we've all got keys. These shiny aluminum keychains are thin enough to ride along with your mail, no problem. $0.69 each with 1-location laser engraving or 1-color 1-location imprint, $50 setup, minimum order quantity 250.

Microfiber Screen Cleaner Everybody hates fingerprints on their phones, tablets, MP3 players, and other tech devices. This little square has microfiber on one side for screen cleaning, and the other side is sticky so it can cling to the back of the device when not in use. It comes packaged with an instruction card that also gets your logo imprinted on it. Around $1.00 each with 4-color process imprint, $150 setup, minimum order quantity 2,000.

Temporary Tattoos This one kind of depends on your brand image. We're not certain that people would want to rub an investment bank's logo onto their bodies, but hey, feel free to prove us wrong! The best thing about temporary tattoos is that they're quite inexpensive - often just pennies apiece - and don't add a bit of extra postage.

Consider inviting people to post pictures of themselves wearing the tattoos on your social media sites for even more promotional value. Sizes vary from 1.5" x 1.5" to 4" x 6", free setup, minimum order quantity 1,000.