[GTM glossary](/glossary.md) Bidstream data Signals & Intent # Bidstream data In short Bidstream data is the information sent along with a bid request when an ad space is auctioned in real time. It can include a device or cookie identifier, the page or app, approximate location, and the user agent, and it is shared with many bidders in each auction. Some intent vendors use bidstream data to infer what people are researching, then try to map that to companies. It is one of several intent sources, and one of the noisier ones. ## How it works When a page loads, an ad exchange sends a bid request to potential advertisers. Each request carries signals about the page and viewer. Companies that receive these requests can store them, even when they do not win the auction, and analyze them for interest patterns. --- ## Why it is controversial in B2B * **Weak company mapping:** Identifiers often point to devices or networks, not a named employee or account. * **Topic accuracy:** Page context is inferred, so a visit does not always mean research intent. * **Privacy and consent:** Regulators and industry groups have scrutinized how this data is collected and shared. Rules vary by region; this is not legal advice. * **Coverage skew:** Data reflects ad-supported pages, which may not match where your buyers research. --- ## How to evaluate bidstream-based intent * **Ask about the source:** Find out whether a vendor uses bidstream data, and how. * **Ask about mapping:** How are devices tied to companies, and how is uncertainty handled? * **Test against outcomes:** Check flagged accounts against past wins and non-wins. * **Check consent practices:** Ask what the vendor does to meet requirements in your target regions. --- ## Alternatives First-party engagement from your own properties, consent-based publisher co-op data, and event signals like hiring or funding are other sources. Many teams combine several and trust accounts flagged by more than one. --- ## Bidstream data FAQs **What is bidstream data?** Bidstream data is the information passed between ad exchanges and bidders during real-time ad auctions. It can include device identifiers, the page or app being viewed, approximate location, and other details, and it is sent to many parties for each auction. **Is bidstream data used for B2B intent?** Some vendors use it to infer topic interest and map activity to companies. The approach has accuracy limits because identifiers are often tied to devices rather than named business accounts, so many teams treat it as a weaker signal. **Is bidstream data accurate?** It is directional at best. Page context is inferred, and linking a device or network to a specific company is imperfect. Testing flagged accounts against your own past deals is the practical way to judge a vendor. **Is bidstream data legal to use?** It depends on region, consent, and how the data is collected and used, and scrutiny from regulators has grown. Ask vendors how they handle consent and consult your legal team. This is general information, not legal advice. Share term --- ## More related phrases * [Third-party data](/glossary/third-party-data.md) * [Supply-side platform](/glossary/supply-side-platform.md) * [Signal-based marketing](/glossary/signal-based-marketing.md) ## Similar phrases * [B2B intent data providers](/glossary/b2b-intent-data-providers.md) B2B intent data providers collect and sell buyer research activity, mapped to companies and topics. Learn what they offer, how their data differs, and how to evaluate one. * [First-party intent](/glossary/first-party-intent.md) First-party intent is buying interest you observe directly on your own channels, such as website visits, content use, and product activity, rather than buying it from an outside provider. * [Intent data](/glossary/intent-data.md) Intent data captures behavioral signals, such as research activity, content consumption, and hiring, that show an account is likely to buy soon. * [Third-party intent](/glossary/third-party-intent.md) Third-party intent is buying interest inferred from research activity on sites you do not own, such as publisher networks and review sites, used to find accounts researching a topic. * [Real-time bidding (RTB)](/glossary/real-time-bidding.md) Real-time bidding (RTB) is an automated auction in which advertisers bid for each ad impression in milliseconds, as a page or app loads for a user.