Supplier User Matching

As the Supplier and BidSwitch sit between the end-user and the Buyer, user matching is important as it allows a Buyer to know the potential value of a user, and thus make calculated decisions to serve the most appropriate advertisements. Additionally, it can increase CPM and media spend to Suppliers . It is therefore in both parties best interests to sync their cookies appropriately. Use the information int he following sections to get the most out of user matching.

Bid Request Fields

User matching, or cookie syncing, is the process of matching an Supplier cookie ID to a Buyer cookie ID. BidSwitch has an integrated user matching functionality to facilitate this between Buyers and Suppliers .

When receiving a bid request from a Supplier, BidSwitch expects both the BidSwitch User ID and Supplier User ID to be sent in the buyeruid and id fields of the User Object.

Supplier Buyer User Matching
Supplier to BidSwitch Bid Request BidSwitch to Buyer Bid Request

Supplier User Matching Flow

  1. The user lands on a page, which runs a Supplier tag
  2. The Supplier tag runs on the page and drops a cookie to the user browser (e.g. SSP_cookie_1234)
  3. The Supplier tag redirects to a BidSwitch cookie sync pixel
  4. BidSwitch drops a cookie to the users browser (e.g. BSW_cookie_54321)
  5. BidSwitch redirects to a randomly selected Buyer pixel from amongst the Buyers listening to the Supplier‘s traffic
  6. The Buyer drops its cookie (e.g. DSP_cookie_9876) and redirects to BidSwitch with its cookie
  7. BidSwitch stores the Buyer cookie ID (DSP_cookie_9876)
  8. The Supplier receives the BidSwitch cookie ID (BSW_cookie_54321)
  9. The Supplier matches the BidSwitch cookie ID with its cookie ID, and stores them in their database.


Please note that the majority of Suppliers will store the cookie syncing in the user’s browser cache. But for clarification we use the database in the diagram.

When all parties have synced their cookies, bid requests from the Supplier to BidSwitch will contain the BidSwitch cookie ID. BidSwitch will then match and retrieve the Buyer cookie ID from the BidSwitch database and send it to the correct Buyer. This enables the Buyer to use their cookie ID and bid intelligently.

Supplier Initiated User Sync

Suppliers should sync users using the BidSwitch user sync URL. Once synced, BidSwitch redirects the user to the Supplier‘s sync URL, this endpoint is completely up to the Supplier and you can check what link BidSwitch is syncing with on the UI Settings page.

Supplier Initiated Cookie Sync Endpoint

## Syntax$SSP_NAME&user_id=$SSP_UID

## Example


Fields marked with asterisk (*) are optional.

HTTP Request Parameters
Value Type Description
ssp_id string The ID assigned to the Supplier by BidSwitch, for example, sspname
user_id* string

The Supplier user ID. This is the value normally passed in the field in OpenRTB bid requests.

Note: This parameter is highly recommended for browsers that do not support 3rd party cookies, e.g. Safari and IOS_App

BidSwitch Initiated User Sync

When BidSwitch initiates a user sync with a Supplier, the process flows in the following manner:

  1. The user lands on a page, which runs a Buyer tag
  2. Running this Buyer tag drops a cookie to the user browser e.g. DSP_cookie_9876, which redirects to BidSwitch
  3. BidSwitch stores the Buyer cookie ID, e.g. DSP_cookie_9876
  4. BidSwitch then redirects to a sync pixel belonging to a Supplier connected to the Buyer
  5. The Supplier receives the BidSwitch cookie ID for this user, e.g. BSW_cookie_54321
  6. The Supplier matches the BidSwitch cookie ID with its cookie ID, and stores them in their database