Optional add-ons: the easiest way to raise your average project value

Optional add-ons raise your average project value by letting clients choose extra work at the moment they are already approving the core project. Instead of offering three packages or selling extras after launch, you show one recommended scope and two or three clearly priced additions the client can switch on with a click.

This article explains why add-ons work, which ones to offer on web projects, how to price them, and how to measure whether they are helping.

Why add-ons work better than packages

The classic advice is to offer good, better and best packages. For web projects this often backfires. The client has to compare three versions of the whole project, each with a different scope, and the conversation turns into which package is "really" needed. Decisions slow down, and many clients pick the cheapest to be safe.

Add-ons change the question. The client first agrees to one scope that you recommend. Then, for each extra, they make a small yes or no decision with a visible price. Each choice is easy, and none of them puts the core project at risk.

There is also a timing effect. Extras offered after launch compete with everything else in the client's budget. Extras offered inside the proposal are part of a decision the client is already making, which is why the same service often sells better as an add-on than as a follow-up email.

What makes a good add-on

A good add-on has three properties.

It is useful but not essential. If the site does not work without it, it belongs in the core scope. Online ordering for a restaurant may be optional; a working contact form is not.

It is self-contained. The client should be able to understand it in one line and you should be able to deliver it without changing the rest of the plan. "Copywriting for five service pages" is self-contained. "More design" is not.

It has a clear price. A fixed price, not an hourly estimate. Clients rarely tick a box next to "billed hourly".

Good add-ons for website projects include copywriting, professional photography, SEO setup, analytics and conversion tracking, extra languages, e-commerce or booking integration, and a maintenance retainer for the first months after launch.

How to price add-ons

Price each add-on as if you were selling it alone, then round to a clean number. Do not discount add-ons to make them tempting; the convenience is already the incentive, and discounted extras train clients to negotiate.

As a rule of thumb, keep each add-on between 5% and 20% of the base project. Below 5% the item feels trivial and clutters the table. Above 20% it is a second project and deserves its own conversation.

Offer two or three add-ons, not ten. A long list of options looks like a menu and pushes the client back into comparison mode. Choose the ones most relevant to this client's goal from the discovery call.

Show the running total. When the client toggles an add-on, the total should update immediately so there are no surprises later. This is one of the main reasons to send proposals as interactive links instead of static PDFs.

A worked example

A freelancer sends a website redesign proposal to a café.

Core scope:

• Discovery and UX: $1,800
• Visual design: $3,200
• Build and launch: $3,600

Base total: $8,600.

Add-ons:

• Online ordering setup: $1,400 (16% of the base)
• Photography half-day: $650 (8% of the base)

Over a quarter, the freelancer sends ten proposals with this structure and wins six projects. Three clients choose online ordering, two choose photography and one chooses both. The add-on revenue is 4 × $1,400 + 3 × $650 = $7,550 across six projects, about $1,258 per project. Average project value rises from $8,600 to roughly $9,858, an increase of about 15%, without changing the core price or sending a single extra sales email.

If the freelancer had offered the same extras after launch, experience suggests only one or two clients would have bought them, and each sale would have needed a separate conversation.

Writing add-on descriptions

Each add-on needs a name and one line that states the outcome, not the task. "Photography half-day: twenty edited photos of your space and menu, ready for the site and social media" sells better than "Photographer on site for four hours".

Mark add-ons clearly as optional and show them unselected by default. Pre-selecting extras might raise the total on paper, but clients notice, and it damages trust in the rest of the document.

Keep the wording consistent between the proposal and the invoice, so the client recognises exactly what they chose.

Measuring the effect

Track three numbers per quarter: the share of accepted proposals with at least one add-on, the average add-on revenue per accepted project, and whether your win rate changes after you introduce add-ons. If the win rate drops, your add-ons may be confusing the offer or the base price may be too high. If nobody chooses a particular add-on for several months, rewrite its description or replace it.

For more on structuring the whole document, see web design proposal template: what to include.

Add-ons without extra work

ProposalKit pricing tables let you mark any line item as optional. The client toggles it on the proposal page and the total updates live, and the selected extras are recorded with the acceptance. You can see it in the templates in the template gallery or create a free account to try it on your next proposal.