The campaigns that fail loudly get fixed fast. The ones that quietly underperform — those are the expensive ones, because they run for months before anyone questions them. Here are the seven leaks I find most often.

1. No conversion tracking

Running ads without tracking conversions is flying blind. You can't optimise what you can't measure, and you'll keep funding campaigns that don't actually produce customers.

2. Sending ad traffic to the homepage

Covered in depth elsewhere, but it bears repeating: a focused landing page can double your conversion rate versus a homepage, for the same spend.

3. Ignoring negative keywords

Without negatives, you pay for irrelevant searches — "free," "jobs," "DIY" — that will never buy. Reviewing search terms weekly plugs this leak fast.

4. No follow-up on leads

  • Most enquiries that don't convert simply weren't followed up.
  • Speed matters: replying within minutes vastly outperforms hours.
  • A simple LINE auto-reply buys you time and keeps the lead warm.

5. Judging campaigns too early — or too late

Killing a campaign after three days is as costly as letting a loser run for a year. Give tests enough data to be meaningful, then act decisively.

6. One ad, never tested

If you've never run a second version of an ad, you don't know if your one ad is good — only that it's the only one you've tried.

7. No mobile optimisation

The majority of Thai traffic is mobile. A page that's slow or awkward on a phone loses the customer before they ever see your offer.

You rarely lose to one big mistake. You lose to seven small ones running unnoticed at the same time.

Audit your marketing against this list. Fixing even three of these usually pays for itself within a month.