If you’re running Google Ads for your North London business, you’ve probably tinkered with bid strategies at some point. You increase bids, watch impressions go up, and assume things are working. Then your CPA climbs and you’re not sure what went wrong.

Most business owners and even some PPC managers focus on the wrong metrics when testing bid strategies. They look at clicks, impressions, and conversion counts. But those are surface-level signals. The real measure of whether a bid strategy change is working comes from deeper data: conversion value, customer lifetime value, and actual business outcomes.

Here are the four key principles you need to understand before you change your bid strategy again.

Principle 1: Conversion Value Trumps Conversion Count

A conversion is not a conversion. Selling a £50 item is not the same as selling a £500 one. Yet most Google Ads dashboards make them look identical if you’re not watching conversion value carefully.

When you test a new bid strategy, your conversion count might stay flat while your conversion value increases by 20%. That’s a win. But if you’re only checking the conversion tab, you’ll miss it and assume the test failed.

Set up conversion value tracking in Google Ads if you haven’t already. If you sell products, connect your shopping feed and let Google track transaction values automatically. If you’re service-based, assign a value to each lead or booking type. A qualified lead from your area is worth more than a page view, so assign it accordingly.

Once conversion value is flowing into Google Ads, use it as your primary metric when testing bid strategies. A strategy that increases conversion value per pound spent is the one that moves your business forward, not necessarily the one that gets the most conversions.

Principle 2: Time-Based Analysis Reveals the Real Picture

Bid strategy changes take time to settle. If you adjust your strategy on a Monday and evaluate it by Wednesday, you’re looking at incomplete data. Most bid strategies in Google Ads use machine learning, and that learning happens over days and sometimes weeks.

Always segment your data by time period when testing. Run your control strategy (the one you’re currently using) in parallel with your test strategy for at least 2 to 4 weeks. Track conversion value by week, not just the total. You’ll often see a dip in the first week as the algorithm learns, then improvement in weeks two and three as it optimises.

If you stop a test after one week because the numbers don’t look great, you’re probably abandoning something that would have worked. Conversely, if you stick with a failing strategy too long, you waste budget. The 2 to 4 week window is your sweet spot for most small to medium businesses.

Principle 3: CRM Data Is Your Ground Truth

Google Ads conversion tracking is helpful, but it’s not complete. Some customers click your ad, visit your site, don’t convert, then call you a week later. Some people see your ad, think about it, then come back through direct traffic. Google Ads records neither of these as conversions from your ads.

Your CRM or sales software is the source of truth for what actually happened. If you use HubSpot, Pipedrive, or even a simple spreadsheet, that’s where you’ll see which customers actually bought and which deals closed from which source.

When testing bid strategies, pull your actual customer data from your CRM. Match it against the conversion data in Google Ads. You’ll likely find that some of your conversions in Ads don’t match real sales, and some real sales aren’t tracked in Ads at all. Use this gap to make smarter decisions.

For example, if you’re comparing a manual bidding strategy to a target ROAS strategy, look at the actual closed deals from each approach. The one that generates more qualified leads and higher-value customers wins, not just the one with more Ads conversions.

Principle 4: Testing Requires Proper Experimental Design

The easiest way to make a testing mistake is to change multiple things at once. You adjust your bid strategy, pausing some campaigns and boosting others, then change your ad creative. Three weeks later, your conversion value goes up. Did the bid strategy do it, or the new creative? You don’t know.

Test one thing at a time. Pick one bid strategy change and apply it to a subset of your campaigns. Keep everything else identical: same budgets, same audiences, same creative, same keywords. Run the test in parallel with your control campaigns for the full 2 to 4 week window. Then compare conversion value and CRM outcomes side by side.

This is the only way to isolate what actually works for your business. If you’re managing ads for multiple services or locations, test within one service or location first. Once you’ve proven the strategy works there, roll it out more broadly.

Putting It Together: A Real North London Example

A local plumbing company we worked with was running Google Ads with manual CPC bidding across Finchley, Hendon, and Barnet. They wanted to test whether target ROAS bidding would improve their results.

They looked at conversion counts from Ads and saw roughly the same number of conversions with both strategies. They assumed target ROAS wasn’t working and switched back.

We reanalysed their data by conversion value and CRM outcomes. The target ROAS strategy was attracting higher-value jobs on average. Manual CPC was generating more bookings, but many were emergency callouts worth less margin. When we looked at actual profit by customer, target ROAS won by 18%.

We tested it properly the second time: target ROAS in Finchley and Whetstone, manual CPC in Hendon and Mill Hill, for four weeks. The conversion value per pound spent improved by 23% in the test areas. After four weeks, they rolled target ROAS out across all areas and stopped wasting budget on low-margin work.

Your Next Step

If you’re currently testing bid strategies or thinking about it, audit your measurement setup first. Do you have conversion value tracking? Is your CRM connected to your Ads account? Are you testing long enough to let machine learning kick in?

Many North London businesses are leaving money on the table because they’re making bid strategy decisions based on incomplete data. The four principles above will help you avoid that mistake.

If you’d like a free review of how your Google Ads are actually performing against your business goals, we offer a free PPC audit for North London businesses. Call us on 020 3355 8773 or visit our SEO and paid media services page to book a time.