Start with #4, for 5 reasons: You know conversion rate optimization (CRO); your target market *needs* conversion help; CRO is a high-priced service; you can do the strategy, implementation, and training required to get it done; and CRO lends itself to value-based pricing as you build your track record in the niche.

You'll have an easier time if you become known as a specialist for "bloggers who want to convert traffic to revenue" or "agencies who need to convert website visitors into leads."

You can always add other services in the future, but start with something where you can make a big impact with your existing skillset and where a market need already exists.

Good luck! Glad to do a Clarity call to answer any followup questions; I've advised agencies in 15 countries.