Numbers only · Updated Aug 2026

Safe Indexing Speed by Domain Age: The Math

Every conversation about drip-feed starts the same way — clients ask what drip-feed indexing is and what it buys them. This page skips the theory and shows the model we actually use: the tiers, the formula, and two worked examples.

The formula

Campaign length is one division away once you know your daily cap:

campaign_days = ceil( total_links / daily_cap )
daily_cap = base_limit(domain_age) × safety_multiplier

Safety multiplier: conservative ×0.6 · balanced ×1.0 · aggressive ×1.5. Aggressive on a domain under a year is the one combination we advise against.

Base daily limits by trust tier

Domain ageTierBase limit
< 1 monthSandbox3 /day
1–3 monthsSandbox5 /day
3–6 monthsEmerging10 /day
6–12 monthsEmerging20 /day
1–2 yearsEstablished40 /day
2–3 yearsEstablished75 /day
3–5 yearsAuthoritative120 /day
5+ yearsAuthoritative200 /day

Source: aggregated SpeedyIndex campaign statistics. These are our working recommendations — not published Google thresholds. Between two speeds, pick the slower one.

Worked example 1: young affiliate site

Input

500 purchased links → target domain 8 months old → balanced mode.

Output

Base limit for 6–12 months = 20/day × 1.0 → 20 links/day. Campaign: ceil(500 / 20) = 25 days. A day-one blast of the same list would hand a 500-domain spike to an 8-month-old site — the exact anomaly spam systems are built to notice.

Worked example 2: aged e-commerce domain

Input

2,000 links → target domain 4 years old → balanced mode.

Output

Base limit for 3–5 years = 120/day × 1.0 → 120 links/day. Campaign: ceil(2000 / 120) = 17 days. Note how tier changes everything: the same 2,000 links on an 8-month domain would take 100 days — or would be worth splitting into stages.

Why the caps exist at all

Two constraints drive the model. Google's spam systems classify unnatural link patterns, and devaluation happens with no notification — your index rate is the only readout. And crawl capacity is finite: Google's own crawl-budget documentation ties it to a site's health and popularity, so a day of bot attention spent on hundreds of backlink pages is a day your money pages ran on leftovers. Context on scale: in our 2025 study of 1,000,000+ URLs, roughly 40% of new pages were still unindexed a month after publication.

Don't want to do the division by hand? The calculator applies this exact model to your inputs.

Run the free calculator