Does Bavian use conversion value or only the number of conversions?

Both, depending on your tracking. When your conversions carry a value, such as the order value of a sale, Bavian looks at what each campaign brings back for what it costs when it divides your total daily budget. When they don't, as in many lead accounts, it looks at the cost per conversion.

Bidding is separate

How Google bids in each campaign depends on its bidding strategy. Target CPA and Maximize conversions bid for the number of conversions. Target ROAS and Maximize conversion value bid for value. Campaigns Bavian takes over keep their type of strategy. See Does Bavian work with Smart Bidding strategies like target CPA and Maximize Conversions?

To set a goal yourself, such as A return on spend, use the Bidding page in Bavian. See How do I give Bavian instructions or set performance goals?

Good to know

• Bavian leaves page views and basket steps out when it judges results, even if they carry a value.
• The values come from your Google Ads conversion tracking. Bavian can't see your shop's own revenue.