[meiji]

Well that's the problem everyone has with competitor acquisition; how much of it is a business info harvest and how much is real. How about sitting down with them to talk, getting a feel for what they're actually about (asking if they have the money, what the terms might be etc) and then if you're still unsure, "sell" them exclusive rights for a period. It's not ideal and a lot of this is done by feel to be honest as for some companies, initial contacts are a daily thing from competitors and some are rejected outright.

[forcer]

We already had a sitdown, we had a feeling that they are a serious buyer and also believe they have enough cash for the transaction but its just our feeling. We had offers in the past via email but they were probably fishing expeditions, this time its probably not but since we are not looking to sell we thought to get some additional protection using the deposit. However, I have not found any advise how to structure it. What do you mean by "sell exclusive rights" ?

[meiji]

Essentially, you can "sell" rights to negotiate with you exclusively. It's often used so that the seller can focus on a single party but gets a reasonable payoff if the sale doesn't go ahead for any reason. The other party therefore has to commit resource and won't just do it for the sake of doing it. I've usually seen it done when there are, say, 3 or 4 interested parties to narrow it down to 1 in the first instance. On some occasions the party that had exclusivity drops out and it's either a good thing as the other parties are still there or a bad thing as a serious buyer dropping can raise alarm bells.