Tier 1: Ad Intelligence Platforms (Best for Ad Agencies)

These show you WHO is running ads and HOW MUCH they're spending. Gold for prospecting.

Platform Best For Price Key Data
BigSpy Meta, TikTok ads $99/mo Ad creatives, duration
SpyFu Google Ads, SEO $79/mo PPC spend, keywords
Semrush Full competitive intel $129/mo Traffic, ads, backlinks
SimilarWeb Traffic analysis $199/mo Channel mix, referrals
AdBeat Display ads $249/mo Publishers, networks

Tier 2: B2B Contact Databases

Direct contact info for marketing decision-makers.

Platform Best For Price Email Accuracy
Apollo.io SMB outreach Free-$99/mo 85%+
ZoomInfo Enterprise targets $15k+/year 95%+
Lusha Direct dials $79/mo 90%+
Hunter.io Email finding $49/mo 92%+
Snov.io Budget outreach $39/mo 88%+

Tier 3: Free/Scraping Sources

Meta Ad Library (Free)

Google Ads Transparency Center (Free)

LinkedIn Sales Navigator ($99/mo)