If you have a finance blog and wish to put an April Fool's joke on it in the form of an article it may not be a good idea, unless you have a loyal fan following who will appreciate it.
Most people come online looking for some specific information. Those who need entertainment, head straight for the entertainment sites. Google divides its search results according to its definition of niches and a joke on a Finance blog may be misinterpreted as wrong information.
Also remember that many of your visitors may be first-time visitors to your blog. When they see an April Fools joke as soon as they land on your site...well, they might just get confused.
"Not everybody has time to peruse an article in leisurely fashion so it could cause feelings of irritation."
Absolutely! Not everyone has a good sense of humor either. What you might consider a great joke may not be appreciated by your visitors.