Prebid Server bidders with iframe usersync don't support AMP usersync

[bretg]

We found that a number of bidders use iframe usersyncs. These don't work in an AMP environment.

We need the following bidders to either: a) change their usersync details to use redirects instead or b) submit a detailed issue for a specific proposal for PBS to support BOTH iframe and pixel syncing in the appropriate scenario. If we don't hear from you, we'll assume AMP support is not a focus.

• 33across - @thomas-33across
• advangelists - @trchandraprakash
• beachfront - @muncha
• beintoo - @ddantuonobeintoo
• emx_digital - @EMXDigital
• engage_bdr - @yannaingkyaw1986
• eplanning - @chino117
• gamma - @gammassp
• gumgum - @cchang320 , @susyt
• lunamedia - @trchandraprakash
• ninthdecimal - @trchandraprakash
• pubmatic - @PubMatic-OpenWrap
• synacoremedia - @coreykress
• unruly - @unrulydevelopers
• zeroclickfraud - @htang555

[bretg]

After more research, I believe this is an invalid issue. Closing.

[bretg]

Here's some evidence that indicates AMP iframe syncs are in fact a problem

ampproject/amphtml#30193

The AMP team decided to restrict all cross domain iframe running in the background.

Further, we have a customer who's AMP match rate for Pubmatic is dismal. We need help on this:

1. does anyone have any additional knowledge about whether an AMP-iframe recursively supports other iframes?
2. Can @PubMatic-OpenWrap provide an alternate pixel-based sync for us to try?

[bretg]

We're testing this now -- Pubmatic has provided a pixel sync and early signs are that match rate for AMP has improved.

[bretg]

We've found that pixel syncs make a difference in the AMP environment. We recommend to all of the adapters noted above to consider whether AMP support is important to them.

In the meantime, we've opened #1554 to address this in a general way, so closing out this issue.