YouTube service types
Views, subscribers, likes and watch time are the staple services. Watch time is usually priced per hour rather than per 1K.
Views: retention is the real metric
Two "views" services at the same price can behave completely differently. Look for stated retention (e.g. "1–2 min retention") and realistic daily speeds. Extremely fast, zero-retention views are the lowest tier.
Subscribers: drop rates vary widely
Subscriber services are among the most volatile. A meaningful refill window (30+ days) matters more here than a slightly lower price.
Watch time
Often bought toward monetisation thresholds. Check the minimum video length required by the service — most watch-time services need videos over a certain duration to deliver.
Bottom line
Compare the specific service descriptions, not just the headline price — and always test with a small order first.