Pricing & the queue
When more than one ad is live on the same space, display time isn't divided evenly between them — it's proportional to what each one pays per day.
Example: Bob's ad runs at $1/day and Sarah's at $9/day. Between them that's $10/day, so Sarah's ad shows roughly 90% of the time and Bob's about 10% — in 30-second turns, spread evenly across the rotation rather than clumped together (so it looks more like Sarah, Sarah, Sarah, Bob, Sarah, Sarah... repeating, not nine Sarah slots in a row followed by one Bob slot).
This is why nobody is ever guaranteed 100% of the display time just by being live — if someone else joins at a higher rate, the split shifts to reflect it. Advertisers see this explained, plus a live estimate based on who's currently sharing the space, before they submit or bid.
This only matters when a space allows more than one advertiser. With max advertisers set to 1, whoever's live gets the whole slot.