Twitter has partnered with Compete for another study that shows that exposure on Twitter is good for business. This time, they looked at Twitter’s effect on online shopping by analyzing 7,600 users and their purchasing behavior as it pertains to 700 retailers on Twitter.

Here’s the gist of the study: People who see tweets from retailers are more likely to purchase a product.

Twitter users who see retailer Tweets are more likely to make online purchases. During the timeframe that Compete analyzed, 27% of general internet users bought something from a retail website. Twitter users, however, made purchases at a rate of 33% from the same sites during the same period. When Twitter users were exposed to a Tweet from a retailer, that purchase rate increased to 39%. This represents a lift of 1. 4X and 1.2X, respectively, and is true across a variety of retail categories.

Furthermore, quantity matters:

The more retailer Tweets people see, they more they visit retail sites and make online purchases. As people are exposed to more retailer Tweets, the likelihood that they will visit a retail website and make online purchases grows. Twitter users exposed to Tweets from retailers on 12 or more days were 32% more likely to purchase from those retailers compared to all users exposed to retail Tweets.

Twitter payed for another study back in October than looked at Twitter’s influence on political donations. That study found that simply being a Twitter users increases a person’s likelihood of visiting a campaign donation page. Furthermore, “this likelihood increases when Twitter users are exposed to political Tweets either from political handles they follow, retweets by users they follow, Promoted Product campaigns by a political handle, or searches on political terms. Twitter users exposed to any of these kinds of political Tweets are almost twice as likely (97%) as other Twitter users to visit an online political donation page.”

Like this most recent study, that study is a pretty strong argument for making your tweets have a larger reach through Twitter’s family of promoted products (tweets, accounts, and trends). These studies are obviously beneficial to Twitter’s advertising strategy, but that doesn’t mean that they aren’t true. Exposure can indeed drive a lot of things – purchases being one of them.

You can check out Twitter and Compete’s full report here.