Tobacco retailers are a key target audience for tobacco product advertising, yet little is known about the messages and channels used to market electronic nicotine delivery systems (ENDS) to retailers. We assessed expenditures for business-to-business print advertising for ENDS in the United States, by year and by advertiser, from 2015 to 2020; and the content of advertisements placed in 2020. The total number of ENDS brands placing business-to-business advertisements declined from 45 in 2015 to 6 in 2020; spending declined from $2.6 million in 2015 (for 283 occurrences) to $492,789 in 2020 (69 occurrences). Across years, the top-spending advertisers were Logic ($1.9 million), blu ($1.0 million), JUUL ($625,050), NJOY ($373,126) and Vuse ($322,075). Common messages of advertisements placed in 2020 included that products are not intended for minors; brand market share; health warnings; profitability or revenue potential for retailers; and flavours. This study suggests that ENDS companies anticipate that ENDS retailers are interested in stocking products that maximise profits, appeal to consumers and comply with regulatory requirements. Declines in the number of advertisers mirror the overall consolidation of the ENDS industry that occurred during the study period. Business-to-business print advertising represents an important channel in which ENDS brands communicate a variety of messages about their products directly to potential retailers.