People use overture because its old skool way of buying domains if I'm being honest.
I have done the same, had an idea for a domain, e.g casino, do a search for casino and got the results through.
casino this
casino that
Oh this domain is available casinomoney it has 578 searches per month for it.
But you can have a domain like that and it not earn you money, personally I think its only the top top top type ins that earn money like casino.
A lot of myth surrounding overture is I think old hat as search engines particually google change and sometimes if you look at results sometimes if you do a search for a particular word, sometimes its only 2 obviously names that are there.
The rest are more brand names, I have let domains go because they havent met what I was hopeing for them
http://www.christmas-january-sales.co.uk/ is I think being dropped in 2008, I could have probaly turned it around and done something else with it, but it's got three main words in it, christmas, january and sales but with hyphons.
So a lot of the old style tricks are losing steam and the modern era of search engines are slowly coming upon us.
The market will probaly drop for domain name selling in the end and a big massive crash whats the point of having a domain if its not making money?
Once people realise this and see this then it will be like the wall street stock crash and the really valuable domains will rise in value.
** Update
Just to prove a point
http://www.google.co.uk/search?num=100&hl=en&q=christmas+sales&meta=cr=countryUK|countryGB
http://www.google.co.uk/search?num=100&hl=en&q=january+sales&meta=cr=countryUK|countryGB
http://www.google.co.uk/search?num=100&hl=en&q=christmas+january+sales&meta=cr=countryUK|countryGB
If I done SEO work on it then it might be up there but as it is then most is from the BBC or other related websites, shopping sites hardly get a look in.