First of all, here is the usual disclaimer. I am not an attorney. This is not offered as legal advice. Consult an attorney regarding all legal matters including contract law.
My experience has been a verbal offer is more often a fishing expedition. You know, "a run it up the flag pole and see if anyone salutes" approach.
Something I was taught in my very first real estate licensing course years ago was a real estate contract had to be in writing to be enforceable in Florida.
So, when I work with clients I always put real offers on paper. A written offer with clearly defined terms, dates and contingencies is always the best approach.

In a market with decreasing inventory and increasing prices, wasting time "fishing" when one is seriously interested in a property may result in "the one" getting away!
The real estate listing agreement commonly used in Florida allows for a seller to determine at the time of listing to receive verbal offers. Most check the box "no."
If you are serious go the extra step and put it on paper. In this digital age an offer and an electronic signature is all that is required - written but no paper involved.
Considering selling your Viera, Florida home? Call me at 321-693-3850. This is the time to sell and move up before prices rise even more.