The way It works is i choose the best app in a specific category to "promote/suggest" so that someone who is new to Android wants a compiled list of useful apps they dont have to sift through multiple nav apps for example.
Its a good idea..... there are threads like this one that accomplishes the same thing but can be narrow minded to suit a certain flavor of apps.
There is also "most popular" in the marketplace... but somehow it seems lots of useless very low rated apps get there too.... can't figure out how low rated apps make it to "most popular"... unless they are paying to get there or the ideal is good but the app is bad so there are lots of downloads but lots of people unhappy with what they get.
Its always better to put a house on the market "ready to sell" rather than fix it up as you go because by the time you get it fixed up really nice to sell, everyone has already either seen it or heard about it and it has a "bad" reputation.
Even so apps shouldn't be released half baked.
On the other hand.. its hard for programmers to recreate and have all the devices we have and the combination of apps we all have installed.
But some apps have no excuse.. they are just trash and should have never been released.....
These are the apps I would hope you would keep off your site.
Basically make sure the ratings are 80% or higher.. otherwise your site will get a bad reputation too as being an unreliable source for finding good apps.
You will also have to resist the tempation to accept advertising from trashy apps that are half baked.
Your reputation will be your bread and butter... not the ads themselves.
If customers and programmers learn they have to "earn" their way to get on your site, it will mean something to be there and it will mean something for us to go out of our way to check it out.
Otherwise, it will just be another site among thousands trying to make a buck and will not be notable.
Thats my humble opinion.