Searchbox from Yahoo - free-of-charge, simple web search experience

My recent task was: integrate searching engine into a website.
Although own searching mechanism was built in that website the client wanted a real world solution, developed by more experts and looking similar to popular search results. The reason and advantages of integrating a search engine are: searching selected domains (one/own or many) for a keyword, give users direct or leading to what they are looking for. After crawling the web I noted a few solutions. Among them were the biggest: Google and Yahoo. All of them serve ads or not when buying a licence. These are a significant arguments while choosing a supplier: displaying/hiding ads, cost of a licence, customizing the look, simplicity and the way of integration.
I choosed a Yahoo solution which fits best our requirements.

Description of BOSS Hosted Search

More: http://boss.yahoo.com/
It is an iframe solution - it means: search results are loaded into iframe (this content will not be visible by search engines). Simple because of just a few steps of configuration and integration. User has many options to customize in administration panel. It is the free option of Yahoo Search solutions.

Integration steps:

-prepare a html form or just a text input element
-create html element (div, span or jQuery popup dialog window with a div in it) where the results will be shown
-include a yahoo served javascript file
-call a js function firing loading Yahoo's iframe into our html element

Advantages:

making money with search advertising
completely free-of-charge
basic Javascript coding skills are required to embed
no limits on traffic to serve the user
can be used commercially free-of-charge
partners are automatically considered for revenue share (Yahoo Site Search solution requires to be approved)
enables autocomplete in searchbox
enables search only own website

Disandvantages:

ads are a default part (visible in iframe)
no debugging option
search results links are loaded into the same browser's window, so going here back (by pressing backspace on destination page) is not possible without additional programming

Conclusion:

Yahoo search solution is really free-of-charge and functional.