Using Performance Tracking to Justify a Site Rebuild to Stakeholders

You know the site needs a rebuild. It's slow, the code is spaghetti, and performance is getting worse with every feature addition. But stakeholders want numbers, not opinions. Here's how to use performance data to build an airtight business case.

The Problem with "Our Site Is Slow"

Telling stakeholders the site is slow doesn't work because:

• "Slow" is subjective — it loads fine on their MacBook
• There's no connection to business outcomes
• The cost of "doing nothing" isn't quantified
• The cost of a rebuild seems high with uncertain returns

You need to translate performance metrics into dollars.

Step 1: Document Current Performance

Run comprehensive audits and record:

Core Web Vitals

Page	LCP	CLS	INP	Status
Homepage	4.2s	0.18	350ms	❌ Poor
Product pages	5.1s	0.25	420ms	❌ Poor
Landing pages	3.8s	0.12	280ms	❌ Needs Improvement
Blog	2.1s	0.05	150ms	✅ Good

Lighthouse Scores

Page	Mobile	Desktop
Homepage	38	72
Product	42	68
Landing	55	81

Historical Trend

Show how performance has degraded over time. "Our Lighthouse mobile score dropped from 65 to 38 over the past 18 months."

Step 2: Connect Speed to Revenue

Bounce Rate Correlation

Pull from analytics:

• Bounce rate for sessions with < 3s load: 18%
• Bounce rate for sessions with > 5s load: 52%
• Traffic percentage in the > 5s bucket: 40%

The Revenue Calculation

Monthly Revenue: $500,000
Sessions in slow bucket: 40% of 200,000 = 80,000
Excess bounce rate: 52% - 18% = 34%
Lost sessions: 80,000 × 34% = 27,200
Conversion rate: 3%
AOV: $85

Monthly lost revenue: 27,200 × 3% × $85 = $69,360
Annual lost revenue: $832,320

Step 3: Quantify the Google Ads Impact

If you're running Google Ads to slow pages:

Current avg Quality Score: 4
Expected QS after rebuild: 7
Current avg CPC: $8.50
Expected CPC at QS 7: $5.50
Monthly ad spend: $50,000
Monthly clicks at current CPC: 5,882
Monthly clicks after rebuild: 9,090
Additional clicks/month: 3,208
At 3% conversion and $85 AOV: $8,180/month additional revenue
Plus CPC savings: ~$3,000/month

Step 4: Show SEO Opportunity

Core Web Vitals Impact

• X% of pages currently fail Core Web Vitals
• Competitor analysis shows competitors pass CWV
• Estimated organic traffic lift from passing CWV: 5-15%

Crawl Efficiency

• Slow TTFB reduces Googlebot crawl rate
• New content takes longer to index
• Show Search Console crawl stats trend

Step 5: Build the Cost-Benefit Table

Category	Annual Cost of Status Quo
Lost revenue from bounce rate	$832,000
Google Ads inefficiency	$134,000
Missed SEO traffic	$250,000
Developer time on performance patches	$80,000
Total annual cost	$1,296,000

Category	Rebuild Investment
Development (3-month sprint)	$180,000
Design	$40,000
Testing and migration	$30,000
Total investment	$250,000

ROI: 418% in year one.

Step 6: Reduce Perceived Risk

Stakeholders worry about rebuilds going wrong. Address this:

Phased Approach

"We can rebuild the top 10 landing pages first (4 weeks). If performance improves and conversions increase, we continue."

Measurable Milestones

"We'll track Lighthouse scores, CWV, bounce rate, and conversion rate weekly. If metrics don't improve by milestone 2, we reassess."

Rollback Plan

"Both old and new sites can run in parallel. We can switch back within minutes if issues arise."

The Presentation Framework

Slide 1: The Problem

"Our site loads in 5+ seconds on mobile. Industry best practice is under 2.5 seconds."

Slide 2: The Cost

"This is costing us $X per year in lost revenue and ad inefficiency."

Slide 3: The Solution

"A focused rebuild of our key pages can achieve sub-2.5s load times."

Slide 4: The Investment

"Total investment: $X with a projected ROI of Y% in year one."

Slide 5: The Timeline

"Phase 1 (landing pages): 4 weeks. Measurable results within 6 weeks."

Track Results to Prove the Case

After the rebuild, you need data showing the improvement. BadPageSpeed tracks performance over time so you can show stakeholders the before-and-after impact.

Build your performance case →