搜索广告 SEM

搜索广告是"用户主动找你"的广告形式——转化意图最强的渠道。

SEM 工作原理

Quality Score 解析

"""
Quality Score 模拟计算
"""
from dataclasses import dataclass
@dataclass
class AdGroup:
"""广告组"""
keyword: str
ad_text: str
landing_page_url: str
bid: float  # 出价（元）
# 质量分三要素 (1-10)
relevance: int = 5       # 广告相关性
landing_exp: int = 5     # 落地页体验
expected_ctr: int = 5    # 预估点击率
@property
def quality_score(self) -> int:
"""质量得分 (1-10)"""
raw = (self.relevance + self.landing_exp + self.expected_ctr) / 3
return max(1, min(10, round(raw)))
@property
def ad_rank(self) -> float:
"""广告排名分数 = 出价 × 质量得分"""
return self.bid * self.quality_score
@property
def actual_cpc(self) -> float:
"""实际 CPC (简化) ≈ 下一位 Ad Rank / 你的 QS + 0.01"""
# 简化：QS 越高，实际花费越低
return self.bid * (6 / self.quality_score)
# 竞价对比
ads = [
AdGroup("python 教程", "零基础学 Python", "example.com/python",
bid=5.0, relevance=9, landing_exp=8, expected_ctr=8),
AdGroup("python 教程", "学编程来这里", "example.com/all",
bid=8.0, relevance=5, landing_exp=4, expected_ctr=5),
AdGroup("python 教程", "Python 速成班", "example.com/python-fast",
bid=6.0, relevance=7, landing_exp=7, expected_ctr=6),
]
print("=== 搜索广告竞价模拟 ===")
print(f"{'广告文案':<16} {'出价':>6} {'QS':>4} {'Ad Rank':>10} {'预估CPC':>10}")
print("-" * 50)
sorted_ads = sorted(ads, key=lambda a: a.ad_rank, reverse=True)
for i, ad in enumerate(sorted_ads, 1):
print(f"#{i} {ad.ad_text:<14} ¥{ad.bid:>5.1f} {ad.quality_score:>4} "
f"{ad.ad_rank:>10.1f} ¥{ad.actual_cpc:>8.2f}")
print("\n关键洞察: 出价最高不一定排第一, QS 才是降低 CPC 的核心")

关键词策略

"""
关键词分类与出价策略
"""
KEYWORD_TYPES = {
"品牌词": {
"示例": ["Nike 官网", "星巴克 外卖"],
"意图": "导航型 — 找特定品牌",
"竞争": "低（你的品牌）",
"CPC": "¥0.5-2",
"CVR": "10-20%",
"策略": "必投，防竞品抢量",
},
"产品词": {
"示例": ["运动鞋 推荐", "咖啡机 哪个好"],
"意图": "商业调研 — 比较产品",
"竞争": "中高",
"CPC": "¥3-10",
"CVR": "3-8%",
"策略": "核心投放，优化落地页",
},
"通用词": {
"示例": ["怎么减肥", "学英语"],
"意图": "信息型 — 寻求知识",
"竞争": "高",
"CPC": "¥5-15",
"CVR": "1-3%",
"策略": "谨慎投放，用内容页承接",
},
"长尾词": {
"示例": ["2024年 500 元以下 蓝牙耳机 推荐"],
"意图": "精准购买 — 细分需求",
"竞争": "低",
"CPC": "¥0.5-3",
"CVR": "5-15%",
"策略": "大量铺设，性价比最高",
},
}
print("=== 关键词分类策略 ===")
for ktype, info in KEYWORD_TYPES.items():
print(f"\n【{ktype}】")
print(f"  示例: {', '.join(info['示例'])}")
print(f"  CPC: {info['CPC']} | CVR: {info['CVR']}")
print(f"  策略: {info['策略']}")

匹配类型

广告结构最佳实践

否定关键词

"""
否定关键词管理
"""
NEGATIVE_KEYWORDS = {
"通用排除": ["免费", "下载", "破解", "盗版", "是什么", "百科"],
"B2B 排除": ["个人", "家用", "便宜", "学生"],
"高端品牌排除": ["便宜", "打折", "二手", "仿品", "山寨"],
}
print("=== 否定关键词清单 ===")
for category, keywords in NEGATIVE_KEYWORDS.items():
print(f"\n{category}:")
for kw in keywords:
print(f"  - {kw}")
print("\n作用: 排除不相关搜索，节省 15-30% 无效花费")

小结

下一章: 社交媒体广告