I used three of the ten images that Adobe Stock gives away to new ussers to make a poster for the college. I have got the license and I can distribute that poster around the university without problems, can't I?
Could you please let us know the kind of posters you are creating with the assets licensed from Adobe Stock? Are they HD posters? Are you using these posters for reselling purpose?
Note: Any asset used for merchandise or for reselling purpose requires an extended license. Also, the licenses which are allocated to your account(as a part of the 10 standard assets per month plan, 1 st month free) only entitles you to license standard assets.
The standard license also allows up to 500,000 copies or views of the asset.