Smart bidding without prior conversion signal performs poorly for the first several hundred dollars of spend. The bidding algorithm needs data points to optimise against, and a fresh account simply does not have them. Pre-warmed accounts solve this with a borrowed track record — usually two to twelve weeks of campaign history under the same Google identity.
The trade-off is cost. A pre-warmed account with $1500 spend history typically costs three to five times what an aged but unwarmed account costs. The premium is worth it when your campaign cannot afford a thirty-day learning phase. It is wasted when your campaign would build its own signal naturally within the first week.
Vendors describe spend history with varying honesty. Some quote total lifetime spend; others quote spend over the last ninety days; others quote spend on a single specific keyword cluster. Operating buyers should ask three questions: how much spend, over what time window, and on what type of campaign. Without all three, the spec is not actionable.
