The expansion of online marketing with regards to promotional giveaways has facilitated the rise of "Freebie sites" that seek to aggregate all promotional free sample offers in one place. These sites will often compile free product samples from all over the World Wide Web and categorize them by type. Some product sample offers may require consumers to complete a survey or refer a friend in order to qualify for the freebies. When all requirements are fulfilled, the product samples are shipped to the consumer.