Your list has a business name, a city and a website. Your emails still read like everyone else's, because those three facts are all you can say. Custom fields are how you add the detail that makes a message feel written for one person: a specific observation, a service they offer, a problem you spotted. They are also how campaigns break, when a column is empty and someone receives "Hi ," or "I loved your post about ."
This guide covers one job: getting your own data into a campaign so it shows up correctly in every email. You can do all of it today with a spreadsheet and an hour.
Decide what a custom field is actually for
Before adding columns, ask what sentence each field will power. A field earns its place only if it changes what you write.
Good custom fields usually fall into three types:
- Observation fields. Something you noticed: "no online booking", "site not mobile friendly", "no reviews replied to".
- Segment fields. A label that decides which version of a message someone gets: "emergency service", "residential only", "multi-location".
- Reference fields. A concrete detail you can mention: a service page, a recent project, a neighbourhood they cover.
Avoid fields you would fill in for only a handful of leads. A column that is blank for most of the list forces you to write around it, and that is where awkward emails come from. If you are not sure which details matter, your ideal customer profile is the place to decide that first.
Step 1: Build the columns in a spreadsheet
Start in a plain spreadsheet. One row per lead, one column per field. Keep column names short, lowercase and without spaces, such as observation, service, segment. Odd characters in headers cause mapping errors in many tools.
Write every value so it reads correctly mid-sentence. Test this literally: say the sentence out loud with the value dropped in.
| Column | Bad value | Good value |
|---|---|---|
| observation | No booking. | there is no way to book online |
| service | ROOF REPAIR | storm damage repairs |
| area | Austin, TX 78701 | east Austin |
Lowercase starts, no trailing full stops, no all caps. The sentence around the field supplies the grammar; the field supplies the fact.
Step 2: Fill gaps or remove the row
Go through every custom column and look for blanks. You have three choices for each empty cell:
- Fill it with real research if the lead is worth it.
- Use a neutral default that still reads naturally, such as "your services" for a missing service.
- Move the lead to a separate list that gets a version of the email without that field.
Option three is often the cleanest. Two honest emails beat one email with a fallback that sounds vague. Sorting the sheet by each custom column puts all blanks together so you can handle them in one pass.
Also check for stray spaces, duplicated rows and values pasted with line breaks. These show up as strange gaps in the sent email.
Step 3: Import and map the fields
In GetClient, you can import a CSV into My Leads and keep extra columns as custom fields, alongside leads you found with the Google Maps scraper. The scraped data already covers business name, website, city and category, so your spreadsheet only needs the extra columns you researched.
When importing into any tool, check the mapping screen carefully. Confirm each column lands in the field you expect, and that the email column maps to email. Open two or three leads afterwards and read the stored values to confirm nothing shifted a column.
Step 4: Write the email around the fields
The standard fields work as merge tags written exactly like this: {{params.name}} for the business name, {{params.firstname}}, {{params.website}}, {{params.city}} and {{params.category}}. Only that exact form gets filled in at send time, so copy them rather than typing them from memory. The guide to personalizing with merge tags covers those in more depth.
For your own researched details, the safest approach is to build the line in your spreadsheet as a full sentence and use it to choose which version or list a lead goes into, rather than relying on an untested tag. A simple pattern:
Hi {{params.firstname}}, I was looking at {{params.website}} and noticed there is no way to book online. For a {{params.category}} business in {{params.city}}, that usually means calls you have to answer by hand.
Here the observation is the same for everyone in this list because you grouped leads by it in Step 2. Write one short email per segment instead of one email with many moving parts. Fewer variables means fewer ways to break.
Keep a field to one appearance per email. Repeating the business name three times reads like a mail merge, which is exactly what you are trying to hide.
Step 5: Preview every step with real leads
Never send a personalized campaign without looking at real rendered emails. In GetClient, the per-step preview shows a message as a specific lead would see it. Check at least:
- A lead with complete data.
- A lead where {{params.firstname}} is missing, since owner names are not always public.
- A lead with a long business name or unusual website.
If the opening falls apart without a first name, rewrite it to start with something else, such as the business name. Then send one test to your own inbox and read it on your phone.
Check follow-ups too. A field that reads fine in step one can clash with wording in step three. The follow-up email templates show how to keep later steps short so they lean less on custom data.
Step 6: Learn which fields earned their place
After the campaign has run for a while, compare segments. If the list that got a specific observation drew more replies than the one that got a general line, that field is worth researching next time. If not, drop it and save the hours.
Look at replies, not just opens, when you judge this. The breakdown in campaign metrics that matter explains why. Over a few campaigns you will settle on two or three fields that consistently matter for your market, and a research routine fast enough to fill them for every lead.