I would like to buy a small business. Are there any sites that collects businesses that are for sale? I am asking about this in a general way, because that produces answers, which are relevant for more users. In my case I am specifically after buying the rights of Iphone apps. I know that I could contact developers directly, but it is a lot of work and negotiations, which might lead to nothing.
In my opinion, be wary of any business that is for sale. When you buy a business, always ask yourself what you would do differently. If a person is making money, and doing so easily, they have no reason to sell. If you have to change the whole business plan, then don't pay much. If you have to pay much at all, why not just do it yourself from the ground up?
There are a number of websites that collect and show businesses for sale. Beware, however, as some of the larger sites (or sites that brag about how many listings they may have) tend to carry quite a bit of outdated listings information.
What I also did not like was having to wade through all the 3rd party advertising and the various listings which were nothing more than MLM type listings and work at home scams. A listings site that only caters to business brokers and provides an excellent experience for you - the potential business buyer - is what you should look for.
Being in the business brokerage and listings technology market for over eight years now, I decided to design a combination online listings management AND marketing service so that the listings information can be automated by the business brokers listing their current businesses for sale.
I think business for sale has problems. Or they don't have reason to sell it. But if you still want to do so, I suggest you to publish your information on some B2B platform, many people will contact you. Or just search the companies for sale on the internet.
If you're talking about small businesses in the generic sense, you may want to consider looking at commercial real-estate listings. Restaurants, stores, contracting, consulting and other small business for sale, are often listed in commercial real estate directories.
If you're talking about web-based small businesses, then the best directory I know of would be the SitePoint marketplace: http://sitepointmarket.com/