There are several types of user acquisition that companies can use to drive growth for their apps or products. Here are three common types of user acquisition:

1. Organic user acquisition: This refers to users who discover and download an app or product without the help of paid marketing efforts. This can occur through word-of-mouth referrals, app store optimization, or other organic channels.
2. Paid user acquisition: This refers to users who are acquired through paid marketing efforts, such as advertising on platforms like Facebook or Google Ads, or through content marketing or email marketing campaigns.
3. Viral user acquisition: This refers to users who are acquired through a viral effect, where users share the app or product with their friends and network, resulting in more downloads and usage. This can be achieved through features within the app that encourage sharing, or through other marketing efforts that aim to create a viral effect.

Each type of user acquisition has its own benefits and drawbacks, and the right strategy will depend on the specific needs and goals of the app or product. Companies may choose to use a combination of different acquisition strategies in order to drive user growth.