竞价策略

创建商品推广或展示型推广活动时，您可以从三种竞价策略中进行选择。请选择最适合您广告活动目标的策略。此设置适用于广告活动中的所有竞价。

动态竞价 - 只降低

如果您选择“动态竞价 - 只降低”策略，亚马逊将针对不太可能转化为销量的点击实时降低您的竞价。如果我们预测到您的广告不太可能转化为销量（例如搜索查询内容的相关性较低、广告位的效果不佳等），而且亚马逊发现了这个情况，则我们可能会针对此次竞拍降低您的竞价。

动态竞价 - 提高和降低

如果您选择“动态竞价 - 提高和降低”策略，亚马逊将针对更有可能转化为销量的点击实时提高您的竞价，同时针对不太可能转化为销量的点击实时降低您的竞价。

在商品推广和品牌推广中，对于搜索结果首页顶部的广告位，其竞价提高幅度不会超过 100%；对于其他所有广告位，起竞价提高幅度不会超过 50%。如果使用此策略，请在选择竞价时考虑到这一点。这种策略会根据转化可能性按比例调整您的竞价，因此与其他两种策略相比，它可能会让您的广告支出产生更多转化次数。如果我们发现了您的广告更有可能转化为销量的机会（例如，您的广告出现在高度相关的搜索查询内容中、您的广告展示在效果较好的广告位上等），则可能会针对此次竞拍提高您的竞价。如果我们发现了其他不太可能转化为销量的情况，则可能会针对此次竞拍降低您的竞价。例如，对于搜索结果首页顶部的机会，亚马逊目前最多可以将 $1.00 的竞价调高到 $2.00；对于其他所有广告位的机会，则最多可以调高到 $1.50。

展示型推广使用预期 ACOS 和您的竞价来计算最终竞价。如果我们发现了您的广告更有可能转化为销量的机会，则可能会针对此次竞拍提高您的竞价。如果我们发现了其他不太可能转化为销量的情况，则可能会针对此次竞拍降低您的竞价。

固定竞价

对于商品推广和品牌推广，如果您选择固定竞价策略，亚马逊将会一直使用您的确切竞价，而不会根据转化可能性调整竞价。与动态竞价策略相比，固定竞价策略可能会让您的广告支出获得更多展示次数，但获得的转化次数却可能较少。

 亚马逊官网原文详情：

Bidding strategies

When you create a Sponsored Products or a Sponsored Display campaign, you can choose from three bidding strategies. Pick the strategy that works best for your campaign's objective. This setting applies to all bids within your campaign.

Dynamic bids - down only

When you choose the dynamic bids - down only strategy, Amazon will reduce your bids in real time for clicks that may be less likely to convert to a sale. If Amazon sees an opportunity where we predict your ad may be less likely to convert to a sale (for example, a less relevant search query, on a placement that doesn’t perform well, etc.), we might lower your bid for that auction.

Dynamic bids - up and down

When you choose the dynamic bids - up and down' strategy, Amazon will increase your bids in real time for clicks that may be more likely to convert to a sale, and reduce them for clicks that are less likely to convert to a sale.

For Sponsored Products and Sponsored Brands, we won’t increase your bids by more than 100% for placements at the top of the first page of search results, and by more than 50% for all other placements. Take this into account when selecting your bid while using this strategy. Since this strategy adjusts your bid up and down in proportion to likelihood of a conversion, it may deliver more conversions for your ad spend compared to the other two strategies. If we find an opportunity where your ad is more likely to convert to a sale (for example, your ad appearing for a highly relevant search query, on a placement that performs well, etc.), we might increase your bid for that auction. If we find another opportunity that looks less likely to convert to a sale, we might lower your bid for that auction. For example, Amazon can currently adjust your bid of $1.00 up to a maximum of $2.00 for opportunities on top of the first page of search results, and up to $1.50 for opportunities on all other placements.

Sponsored Display uses expected ACOS with your bid to compute the final bid. If we find an opportunity where your ad is more likely to convert to a sale, we might increase your bid for that auction. If we find another opportunity that looks less likely to convert to a sale, we might lower your bid for that auction.

Fixed bids

For Sponsored Products and Sponsored Brands, when you choose the fixed bids strategy, Amazon will use your exact bid for all opportunities and won’t adjust your bids based on likelihood of a conversion. Compared to dynamic bidding strategies, you may get more impressions, but fewer conversions for your ad spend with this strategy.

 文章来源：亚马逊官方网站