A non-profit sector stereotype you've probably encountered is that of a ramshackle soup kitchen with a line of homeless outside. Things like homeless shelters funded by a single church or wealthy individuals ARE out there, but these have not been representative of the sector for many years. Non-profits can be big business, so bring on those promotional products! Regional or nationwide, non-profits need to promote themselves like any other big organization does.
As an example, the YMCA can look a lot like well-oiled business machines despite their non-profit nature. Should this mean that they need to approach promotional items the same way any for-profit business would? It is really quite situational.. One route you might go won't meet the needs of everyone equally, and this applies to a non-profit organization as much as it would for anyone else.
One difference would be the availability of funds to spend on marketing efforts at a non-profit. Thanks to things like profit, money to spend on the less solid things like marketing and branding is more available. Budgets at non-profits can end up very limited, especially because the reputation of a non-profit can be a huge factor in its success. Some non-profits see it as a priority to keep the amount of money they spend towards "administrative costs" as low as possible. How likely are you to give if they seem to spend half of their donations on themselves?
All of the basic ideas apply in the non-profit sector as they do in a business setting. Make sure you keep those promotional items easy to carry but still attention-getting. No one will carry a promotional item around all day if they've been given are heavy or even just bulky. Avoid the temptation to just toss money into purchasing any little trinket you can find, without giving it a lot of thought. Giving out an easy to carry but completely useless promotional product is just going to be a waste of money. Money that may more difficult to come by in a non-profit environment!
Without the big financial safety net, you might be tempted to play it safe in a non-profit setting. Don't do this! It would be best for a non-profit to differentiate themselves by being creative. Charities can attract a younger and creative group of employees or volunteers, so it is important to tap into that creative resource. Take advantage of the fact that many people don't look at non-profits as a business, which can mean more freedom. Picking a promotional item that might not be entirely professional could be a bigger benefit to a brand than a hindrance!
The non-profit sector doesn't have as much interaction with the promotional industry as it should. It is important to not write off the non-profit sector as a source of potential clients, if you're a promotional items seller. They're out there and they need your help! If you are a non-profit, the promotional items out there could be a critical contribution to getting some awareness out there and some contributions rolling in. Our sectors can mutually benefit one another, and society as a whole.