Writing Effective Sales Letters and Emails: A Simple, Low-Cost Strategy to Increase Your Conversions


Want more responses and incoming leads from your sales emails and letters? Then you need to answer the following questions your prospects will have when reading your correspondence:

How do you answer these questions for your prospects? By adding proof.

In this article series, we have been discussing how to craft high-converting sales emails and letters so you can get the highest response rate possible and blow up your revenue. (That’s what we do!)

By the way. If you haven’t read Part 1, start there. We talk about how to speak directly to the prospect to increase the chances of getting your letters read and acted upon.

In Part 2, we talked about proper formatting and layout and we introduced the concept of adding proof in the form of reviews and testimonials.

In Part 3 below, we will go into more detail on exactly how to add proof and do it correctly. Here’s the thing: This isn’t rocket science and you don't need to be a professional copywriter to do it. But there is a specific formula, and that’s exactly what we will teach you in this article.

How can you incorporate proof into your sales copy? Let’s talk about four ways:

Back Up Your Claims Like a Boss: Add Research and Data

Whenever you state a claim, add proof. Otherwise, your prospects will see your claims as lies and pure fluff.

Here’s a key thing you need to remember: People buy with their hearts and emotions. They aren’t always thinking rationally when making a purchase.

When you purchased your last home, what was the driving factor that led to your decision? Yes, you used your brain somewhat, but, let’s face it, if it came down to two options, you would choose the home that made you feel more warm and fuzzy inside.

“This is definitely the one! I know because my brain’s prefrontal cortex is telling me I have to buy it.”

Reliable data gives your prospects the warm and fuzzy feeling they need to take advantage of your offer

In this article series, we have been using the example of a lawn service company. If you owned this company, one of your claims may be that your product kills 96% of customers’ weeds. Simply writing this claim in your email and letter may help. But, showing data to prove this claim will up your chances of getting a response.

Now, this example may be far-fetched (if you kill 96% of weeds and you are out there, please call me) but the point is to back up your claims with data.

What if I don’t have any data?

If you don’t have any data, start testing. Test your products against your competitors or test the value of your own products to show their benefits.

Maybe you sell a DIY car washing tool and you claim that people can wash their car twice as fast with your solution. Perform a test where you use a less-effective car washing tool and compare the time it takes to wash cars using both tools.

Or let’s say you sell copywriting services and you claim that your copy will lift a business’ conversions by 5%. Get data from your clients so you can show the “before and after” results.

The key here is to back up your claims and make the data visual so prospects can trust you more.

A few more tips regarding data:

And lastly, don’t fudge! This goes without saying, but never manipulate data to back up your claims. It will come back to haunt you someday. If you don’t have any data, gather some or start testing.

If it doesn’t make sense to test and use data as social proof for your business, read on.

We have more ways to add proof…

Draw Prospects in with Customer Testimonials

I could sit here all day and talk about how amazing our agency is, how we get amazing results for our clients and how amazing our clients think we are, yada yada yada. Ad nauseam, right? You probably don't care and we don’t blame you.

But, then when we post a happy client testimonial like this…BAM! Instant credibility.

Testimonials are SUPER powerful. 85% of consumers said they read up to 10 reviews before feeling they can trust a business, and 72% of consumers say that positive reviews make them trust a local business more.

The fact is that people don’t want to be sold to anymore. They’re tired of pushy car-salesmen-like brands jamming their self-proclaimed amazingness down their throats.

“This computer is AHHHHMAZING!! Can’t you see that? Ummm, can’t you? Did I tell you how amazing it is?!? Don't you want it right now??? It’s SUPER amazing, wasn't sure if I told you that.”

What consumers really want to know is that you can be trusted and that what you offer will solve their problems. When you can provide proof that others (besides your biased company) use your products and love them, it elevates your credibility.

How to make your testimonials really pop

Testimonials come in all shapes and sizes. Some are awesome and some, well…they’re just plain bad.

Here are two testimonial examples. See if you can figure out which one is better.

#1: XYZ Company is amazing. I loved working with them!

#2: XYZ Company helped me double my traffic in 30 days and my revenue soared as a result.

Which one sounds more compelling? If you said #2 (I hope you did), you are right.

#1 is good, but it doesn’t state any specifics. Why do they love you? What was so good about working with you?

#2 states a benefit and also gets specific with the results (doubled traffic in 30 days).

The best testimonials include quantitative results that prospects can connect with and also state a benefit to using your products and services.

How do you land these winning testimonials?

Ask your customers. Just flat out ask them.

Ask your happy customers the following questions:

  1. What was your favorite benefit you experienced as a result of buying this product?
  2. What were some specific results you achieved?
  3. What feature did you like the best?
  4. Would you recommend this product to others? If so, why?

Then, my favorite question of all…

  1. What were you most concerned about before buying this product?

Now, this last one isn’t necessarily a testimonial-related question. But, since you have your customers’ ear, you might as well get some valuable feedback and use this data in your marketing.

For example, let's say the answers revealed that a lot of your customers were concerned that your product wouldn’t last longer than 30 days. Knowing this, add more copy in your emails and letters that mentions how long your product lasts and stress your longer-than-30-day guarantee.

Display Your Media Coverage

Got media coverage? Then, show it off.

If you were featured in a magazine, newspaper, podcast or even a high-profile blog, mention this in your emails and letters as a form of social proof. It will skyrocket your credibility big time.

Not all media coverage is beneficial, though. Before you go cutting and pasting those clips, here are some things you should know:


If you were featured on Bob’s Lovely Lawn podcast started by your next-door neighbor, this may not be the social proof you want to advertise. If your audience wouldn’t know or recognize the media outlet, adding it could hurt your reputation instead of bolster it.

Ask yourself: Will my prospects recognize and respect the source? If so, use it.


Does the media mention relate to your offer? Your lawn care prospects won’t care about your shrubbery review in Lifestyle magazine. Yes, it’s related to lawn care, but if you are sending a letter to prospects who are more concerned in a weed-free lawn, all of your copy should focus on this, and only this. Adding new shrubs to a lawn really has nothing to do with the focus of the email.

Ask yourself: Is this coverage backing up my claims? Will it really matter to the people reading this letter/email? If so, use it.

Don’t Let Them Get Away: Provide a Fail-Safe Guarantee

Doubt is a sales killer. Doubt turns into hesitation, which turns into an instant trash situation.

People won’t buy if they feel the purchase is risky. And perceived risk always accompanies online purchases.

It’s easier to pull the trigger and purchase a piece of clothing you can try on and feel with your bare hands. But, buying that same piece of clothing online introduces risk.

What if it doesn’t fit?
What if it makes my butt look twice the size?
What if it feels cheap?

E-commerce stores offer returns as a fail-safe for online shoppers who want to minimize this risk and remove the threat that they will be stuck with their purchase forever.

Your prospects won’t be able to physically touch or feel your products or services either. They may not even have any past interaction with you. To eliminate the perceived threat of risk, you need a fail-safe. And this fail-safe is to provide a free trial and/or a guarantee.

A guarantee also shows buyers you believe in your own product. This goes a long way in your business’ quest to be trusted and seen as credible. Trustworthiness and credibility also strengthen customer relationships. Plus, why would you want your customers to be stuck with a product they are unhappy with?

How do you create an effective guarantee that eliminates the appearance of risk?

Here are a few tips:

Here’s an example guarantee:

We stand behind our brand and we pride ourselves on providing the highest quality products to our customers. But, if for any reason you are not satisfied, simply return the product within 30 days and contact us for a full refund of your purchase price, no questions asked.

Your guarantee terms may be different depending on the purchase price and what you are offering, but as long as you state the terms clearly and provide this benefit to customers, it will remove risk and increase conversions.

What if I Don’t Have Any Proof?

You don’t need all four items of proof (data, testimonials, media coverage, guarantee), but at a minimum, we recommend adding testimonials and a guarantee. If you do not have any testimonials, contact your past customers and start gathering some. Offer an incentive if you need to. The point is that proof is vital if you want to maximize conversions for your sales emails and letters.

In the last part of this article series, we will discuss how to ensure high readability for your sales emails and letters and keep your correspondence from ending up in the virtual trash can. See you there!


At Viral Solutions we are committed to seeing YOU succeed. It is our goal to grow your business with proven digital marketing strategies that will help your business for the long haul.

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Filed Under: Business Tips, Content Creation

About Lindsey Perron

As Thomas’ daughter, Lindsey was introduced to the world of sales and marketing at an early age. Curious about what her dad did, Lindsey would jump at every opportunity to help and ride along on sales calls. Always quick to take charge and lead the group—a trait that has only grown with time—Lindsey was frequently told by her parents that she was destined to be a manager or CEO of some sort. While working toward earning her bachelor’s degree in human services from the University of Wisconsin-Oshkosh, Lindsey interned with the UW Office of Equality and Affirmative Action and served on several councils, which gave her the opportunity to develop her persuasive writing skills, researching skills, problem-solving skills, project management skills, and more. After working as the lead teacher of the 4-year-old room at the local daycare center, Lindsey decided to switch gears and join the Viral Solutions team. In her position, Lindsey is able to help clients think through an end goal and reverse engineer it into the steps needed to achieve it.

When she’s not working, Lindsey loves spending time with family, be it traveling somewhere together or just hanging out at home.