Top 5 Paid Media Agencies in California (2026)
The top 5 paid media agencies in California for 2026, ranked by Growth Partner Confidence Score with cited public evidence for every pick.
Updated July 27, 2026 · Compiled and reviewed by Growth Partner Index Editorial Desk
This shortlist ranks the 5 highest-scoring paid media agencies working in California, drawn from the 478 agencies currently in the Growth Partner Index. Ranking is by Growth Partner Confidence Score, which is built from public evidence only.
The agencies below are based in Los Angeles, CA, El Segundo, CA, Costa Mesa, CA. Each entry links to a full profile with the score breakdown, the sources behind it, disclosed budget band, and the services the agency actually staffs for.
Use it as a starting shortlist, not a verdict. A high score means the public evidence is strong; it does not mean the agency is the right fit for your budget, category, or measurement maturity.
The shortlist
Ranked by Growth Partner Confidence Score
- 1
Darkroom is a growth marketing agency based in Los Angeles, CA working with Home Goods and Fashion & Apparel brands. Publishes 3 case studies with named clients and measurable outcomes, including OLIPOP, Crate & Barrel, Everlane.
Full profileVisit website$50k–$250k/mo
- 2
Eboost Consulting is a growth marketing agency based in El Segundo, CA working with eCommerce/DTC and B2B brands. Publishes 1 case study with named clients and measurable outcomes, including Itochu Descente. Rated 4.9 from 15 reviews on clutch.co.
Full profileVisit websiteNot disclosed
- 3
Common Thread Collective is a growth marketing agency based in Costa Mesa, CA working with Ecommerce / DTC and Apparel brands. Publishes 3 case studies with named clients and measurable outcomes, including Dorsal, Igloo, Born Primitive.
Full profileVisit websiteNot disclosed
- 4
Wpromote is a growth marketing agency based in El Segundo, CA working with B2B and Financial services brands. Publishes 2 case studies with named clients and measurable outcomes, including Whirlpool, Klipsch.
Full profileVisit websiteNot disclosed
- 5
KlientBoost is a growth marketing agency based in Costa Mesa, CA working with SaaS/B2B and E-commerce brands. Publishes 2 case studies with named clients and measurable outcomes, including Fashionphile, Segment.
Full profileVisit websiteNot disclosed
How we picked
Agencies qualify for this list by working in paid media and, for location lists, being headquartered in California. Ranking is by Growth Partner Confidence Score, which is built from public, citable evidence only.
Read the full Growth Partner Confidence Score methodology, or submit a correction if something here is wrong.
Frequently asked questions
- Who is the #1 paid media agency in California in 2026?
- Darkroom ranks #1 among paid media agencies in California for 2026 with a Growth Partner Confidence Score of 74/100. Darkroom is based in Los Angeles, CA and is best suited to published work for olipop: 3x revenue growth fueled by the campaign.. Eboost Consulting (69/100) ranks second.
- How were these agencies selected?
- Every agency on this list is scored against the same seven-pillar Growth Partner Confidence Score: proof of outcomes, category fit, creative-media integration, reputation, operating maturity, buyer fit, and freshness. Scores are built only from public, citable evidence such as case studies, press, and interviews. Placement cannot be purchased, and sponsored listings are labelled and never re-ranked.
- What should I look for when choosing a paid media agency?
- Ask who runs the account by name, ask for one case study that discloses budget and an incremental outcome, and ask what measurement stack they bring. Anyone quoting a ROAS target before seeing your data is guessing. Beyond that, confirm the budget band matches yours and that the senior operator named in the pitch is the person who will actually run the account.
- How much do paid media agencies charge?
- Boutique shops take retainers from roughly $5k–$15k/mo, usually with a $10k–$50k/mo media-spend floor. Mid-market agencies sit around $15k–$40k/mo or 8–15% of spend. Enterprise firms rarely engage below $500k/mo in media. Every profile in this index lists the agency's disclosed budget band so you can filter before the first call.