How Are Webistes And Domain Names Such A Good Investment?

I have recently spoke wiith my financial advisor about purchasing domain names and building websites. He said since I have some extra capital to use this could be a very exiciting and lucrative venture. There are two domain names up for auction on godaddy that I am interested in one is www.fasttires.com the other is www.findyourdreamgirl.com. Fasttires is already going for $40,000 and findyourdreamgirl.com is listed for $18,995 my advisor thinks this is a good price to move on before it goes up it could be the next match.com. What do you guys know about these sort of investments I want to build my own web business.