The following databases offer data on advertising expenses broken down by various categories, e.g. by advertising media, industry, product etc.

• Ad$pender
  • Advertising expenditure across 18 media by companies, brands, products in the United States.
• eMarketer
  • Market data and statistics on total advertising spending and ad spending by media globally.
• Statista
  • Market data and statistics on advertising and media, including advertising spending globally.

Expenditure on Political Ads

• Facebook Ad Library Report
  • Get details on how much is being spent on ads about social issues, elections, or politics on Facebook in the United States.
  • Filter ad expenditures by dates, geography, advertiser, etc. For details on individual advertisement, click the name of the ad.
  • See also the Facebook Ad Library API.
• Weslean Media Project
  • Data on spending on political campaigns is available in the below listed database for a small fee.