We run an e-commerce store selling home decor products in the US market. Our monthly ad spend is around $5,500, and most of our revenue comes through Google Ads campaigns. Over the last three months we've noticed an approximate 25% discrepancy between the order count in the ad dashboard and actual orders in our store admin.
The marketing agency we work with claims this data loss is caused by browser blockers and cookie restrictions, and they're recommending we switch to server-side conversion tracking. They quoted a one-off setup fee of $1,200 plus an ongoing $60-$80/month for server hosting costs.
Is this extra expense genuinely worth it for a small business? What do we stand to lose long-term if we don't migrate to server-side tracking, and are the agency's quoted rates reasonable?