The thing is we all have domains and we just have them sat there doing nothing.
If now and again you build a site you would soon have many sites, even if some don't make you any money it will increase the chances of a sale along with the value, for those reasons it can't hurt to give it a go when you have time. . . It can be fun!
I posted earlier ( quite a long time ago) i would build a mini site and blog the results and how i did it, the site I have got completed today and is called
mosquito repeller which is not a very hot topic, but one which i see as a good test.
The basic idea behind this and every mini site is to provide valuable information first and make money second. This is actually my first site focused on adsense so its a test for me also.
It's full of useful information so should be liked by readers and google. If it works as I'd expect then this is easily £1 a week if not per day as most of the others i have done have been.
As i said this is pretty much my first adsense focused site, but i will be adding amazon links tomorrow for the products featured along with images etc. It's not indexed yet but should be fairly soon.
The name mosquito repeller only has around 200 exacts a Month but that shouldn't put you off. A site full of content will pick a lot of long tail searches you never intended it to.
As far as mini sites go this is about 10 pages, some I have made over the past 2 weeks (I've decided to do a lot as i got myself motivated) are only 3 pages but are already making 75p to £1.20 a day via amazon.
I'm not 100% about this adsense stuff yet as I'm against blatant adverts, once it's indexed and I see the stats and bouce rate I might get rid of the adsense altogther.
It's all about content and niche, build the site for users first and the money will follow.