Here are some official industry stats that might be helpful for your business case for purchasing promo products:

52% say their impression of a company is more positive after receiving a promotional product.
76% recall the name advertised on the product.
55% keep the item for more than one year.
Nearly 50% of recipients use them daily.
52% of people do business with a company after receiving a promotional product
Spend less, achieve more and remind people about the benefit of doing business with you.

Promotional Products in the Home:

How many people have at least one promotional product in their kitchens?  91%
How many have 2 or more in their kitchens? 81%
In fact, the kitchen is the #1 place people use and keep their promotional products.
(People spend on average 3-5 hours a day in their kitchens)

Promotional Products in the Office:

How many people have at least one promotional product in their offices?  74%
How many have 2 or more in their offices?  59%
In the work place, more than half of people hold onto their promotional product from 1 to more than 4 years.

Reach & Recall:

71% of business travellers surveyed reported receiving a promotional product in a 12 month period.
7% of this group had the item on their person.
56% of people kept their promotional product for more than one year.

How effective are Promotional Products in staff retention, motivation and brand interest?

75% of Human Resource managers surveyed are using promotional products in recognition programs.
72% of marketing and HR managers said that promotional products are very effective in motivation and retention of staff.
100% of advertisers said that adding a promotional product returned a favourable response to their campaign.
69% of advertisers said promotional products increased brand interest and 84% said it created more favourable impressions of the brand itself.

Understanding the medium:

A product is just a product, until it is linked with a promotion, it then becomes an advertisement.
The most successful advertising campaigns are the result of a planned strategy.
Throwing products at your target market without that planning is a waste of your marketing dollars.
The product is only one component in the whole campaign.
The creativity used to get a response is the key to increasing profits and promoting brands.

Successful campaigns require:

Strategic ‘logistical’ and ‘emotional’ roll out
Action engagement triggers
Data collection analysis
Technical logo application knowledge
Creating the difference between a ‘passive’ and ‘active’ promotion

(Reference: - APPA)