Promotional pens are often used to convey a corporate name and phone number. While this is all well and good it overlooking two important characteristics of a company marketing presence; namely the corporate logo and slogan. These two options appear every where else, be it in signage, print advertising, and even television advertising; however rarely are they used on promotional pens.
One reason that corporate logos are not seen often on promotional pens is that they are sometimes just too darn intricate and do not translate well in to a low resolution image often used on promotional pens. There really is no work around for this, as it's better to not have a graphic than have a muddy barely recognizable one. There are however two possible alternatives to the standard corporate logo if yours is inappropriate for printing on to a promotional pen; either the logo used on company letter head, or creating a special stripped down version of the logo just for printing on pens.
Both have their advantages and disadvantages. If you already have a small logo designed for use on letter heads then this is probably the best option, the disadvantage here is that it is likely not graphically related to your normal logo so it may cause some customer confusion, however it will be the least expensive option. The advantage to using a stripped down version of your corporate logo is that they can usually be made to look quite close to the original, and customers will not be left wondering if they are thinking of the same company. The disadvantage here is that designing a new logo can be expensive if you have to outsource the job, and a small company may not be able to afford the associated cost.
Care must be taken if you decide to put a corporate logo or slogan on a promotional pen as this can lead to an overcrowded pen that ends up looking too busy, and no potential customer will pay much attention to a busy unattractive pen. I definitely would not suggest putting all 4 optional on a promotional pen (logo, slogan, name, and phone number) at the most choose three of the four, with the name and phone number being mandatory then add a slogan or logo to flesh out the design. If you have a really good slogan and no logo just go with the slogan and forget about designing a new graphic. If your company sticks to the slogan and uses it often it can become like a lettered logo and serve the same purpose on a promotional pen.