I've been around the block a few times. Does that mean I've got all the answers? Absolutely not, but what I do have is experience and hopefully that means I've learned not to make the same mistake over and over again. And one mistake I have certainly over come, is being able to read when a prospective client is trying too hard to convince me about why I should take them on.
A few years back I had property developer approach me about doing their marketing. He was telling me a big story about where they were going, how they were going to go international, how much money they were going to make and how big an opportunity this was for me. Then came the clincher, he explained why I should do all of their work for free for the first 6 months to help them get off the ground.
My spider senses were going off early in the conversation simply because he was trying too hard to convince me of how smart it would be for me to do business with them. Fortunately I had been in that exact same spot before, and I have done work for clients based on the potential opportunity - which ninety percent of the time, never materializes.
It's easy to get caught up in someone else's dream, I've certainly done it many times. Does it pay off? Rarely. Why not get caught up in your own dream and make your business the success it should be by getting paid for the work you do.
In my opinion taking on a client and working for free based on "what may be" is a very risky thing to do.
Now there are exceptions. If the potential client has great credibility, if they come highly recommended and they have a proven track record of successful outcomes, it might be worth taking a risk. But they are rare and of course you need to do your homework.
The bottom line for me, get nervous when someone tries too hard to sell you about how great their business will be tomorrow. If they are not prepared to pay you for the work you do today, it's unlikely they will value the work you do tomorrow.