So how long should a sign-up form be? There is, of course, no perfect length for all requirements but we can give limits: running onto multiple pages is a no-no, as is not asking for sufficient information.
There are a number of points to consider when trying to decide how long a particular form should be.
Going with the flow
The subscriber is probably in a positive frame of mind. By signing up they are saying that they trust you with their email address and they will expect some degree of form filling. They will be, to a variable extent, anticipating something beneficial and this can be exploited. So don’t be quite so nervous about the number of boxes putting subscribers off.
Give them the option
Work out what the minimum information you require and then consider the option method. Explain that the only information required is that marked with an asterisk. This is a common method. However, the first sight of a couple of dozen boxes on the form might well put off some subscribers.
How did they arrive
If they came via a clickthrough from your e-newsletter then their familiarly with your business should make them willing to cooperate. Further, you might have certain information about them already, so don’t ask the same questions again.
If they came via a website, for instance from a page which featured a particular range of products, then you will know of their preferences.
Can you get the information another way
In most cases you do not need to know, for instance, their birth date. If you are selling activity holidays then you are after active people and not those of a certain age. You will receive considerable data over a short series of email marketing campaigns and it will be dependable. Accept that for some unaccountable reason, people will lie about their preferences. Very few will have read War and Peace whatever they say.
Work out what the bare minimum of information your require. This might amount to just the email address and name or, if B2B then their position in what company. Then decide what additional information would you need to target your initial emails better.
Prioritise the extra information so you don’t ask pointless questions or ignore the more important material.
In my research for these articles I peruse the methods companies use and my experience is that nearly half of those which depend on email marketing appear to have little concern for the limitations of mobiles. The actual percentage of emails that are opened on smartphones might be in dispute, but all agree it is substantial. If your forms are difficult to complete on them, then that is almost certainly a subscriber lost.
Test and test again
There is no precise number of boxes to include in a form. Some people will be in a hurry, other will be happy to cooperate. It is probable that you can predict which group they favour but to do this you need to test all the time. B2B forms might well need to differ in size from those for B2C, at least for your specific product. Nothing is set in stone.