Making a button appear after an action - good or bad?

Question

I'm working on some kind of B2B checkout process for car dealers who buy cars from my client.

In the 1st step of checkout, they have to choose between pick-up and delivery.

This is what I'm going for (work in progress):

I want the user to really focus on these 2 options. When they'll have selected one, they will need to click on a "go to payment" button to proceed to step 2.

I'm thinking of making the "go to payment" button appear only AFTER they've selected one of the options. The interface would then look like this:

If I were to display the "go to payment" buttons from the start, I'd have to plan for an error message for the case when the user clicks on that button but no option was selected.

I like the idea of avoiding that error message. Without that button, the user would really focus on the 2 options without worrying on what to do next. The button would then appear when relevant.

Is there a risk of the user not noticing that button? I guess it will have to stand out a lot in the final design.

Do you see any other issue with this?

Thanks in advance

Answer 1

I'd simplified the choice a user needs to do, by promoting the Delivery Service as an attractive and valuable offer.

So user need no to think on his choice (less cognitive load). Still, you provide some clues for him to push him gently to using Transport Service:

• Display the distance between locations, providing the data for decison
• Promote Transport Service by highlighting its advantages for the user

The advantages:

• Less choice – less cognitive load. No disabled/hidden buttons!
• More clear UI (you need no to display some details, at least until they will select an option)

To promote the service, you can still display the option on the next (payment) screen, letting them to use it:

Answer 2

Minimize the visual noise and simplify the flow

Give the user a choice, but make it an easy one. Considering your transportation service is most popular, and probably most preferred by your client, you can position this as an offer. The clear choice is to simplify the cognitive load on the user end, by showing them it's easier to just to get their vehicles delivered, rather than having to deal with the hassle of having to pick them up themselves, but they still have the option to do so if they so desire. This also helps by hiding the content for the pick-up option initially, and then displaying only when the user clicks on that option, so the user is not overloaded with information, but be sure to include indication that if they click that option, more information will be displayed, such as a dropdown arrow.

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Transportation Page

^{download bmml source – Wireframes created with Balsamiq Mockups}

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So -- How does this solve the button issue?

Simplifying the flow will allow the button to be more visible, and by having the transportation offer selected by default being most popular/preferred, we can reduce the click depth for the user, and speed up the checkout process. The user can evaluate the offer, choose to accept, and continue to payment with one click, instead of two by clicking on the option, then the continue button, or otherwise choose the pick-up option, which will require that additional step.

Since there is always an option selected by default, there would be no need to disable or hide the button. Once the user has made the conscious decision, they can go ahead and click continue.

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Payment Page

For a fail safe, be sure to include helpful information on the order summary in case a user continues without looking at the offer and is confused by the delivery charge, and provide them an option to pick up their vehicles instead.

^{download bmml source}

Answer 3

I wouldn't suggest that. Alternatively, you can place the button and disable it. Other user actions will enable that button(as per your requirement)

In my opinion, that would be a better practice