What would be the most lucrative self start-up business to go into right now?

I think that would be dependent on how lucrative that you would want the business to be and what your current skills and experiences are concerning work that you have already done.

I run a number of small businesses. Most of the business that I get is from the free ads that I place on the Internet. I'm not getting rich, but I do well enough for me to own my home and be comfortable.

What sort of skills and experience do you already have, please?

Thanks!