I have recently returned from a splendid holiday in Cuba, and I'm pleased to say that my only interaction with a computer was to check my emails (briefly) at the hotel bar, where internet access was available.

As expected, internet cafes were not common on the streets of Havana, which isn't surprising considering the economy of the country.

However, at the same time - through the lens of CNN - I was kept up to date with the excitement generated as Google approached IPO status.

You couldn't find more contrasting scenarios, but the fundamental issue is about access to electronic information. We take such access for granted, but we may be on the cusp of experiencing problems in the way we search the internet.

Effectively the window we use to look into the internet is shaped by just a few. A snapshot over a single month this year showed that Google was handling almost 45 per cent of all internet searches worldwide, with its closest competitor Yahoo at 30 per cent.

These companies possess tremendous power and can make or break businesses, influencing what we visit on the web.

While Google has become a cornerstone of the internet, and has been a much loved and trusted form of searching through the endless information, could its potentially impatient and money-hungry shareholders prove to have a corrosive influence on how the engine searches for information?

Hopefully not, as the technology is what Google is all about, but the rise of keyword advertising may be about to change the dynamics of all search engines.

If my behaviour is anything to go by, I only use the first or second page results from a search, before I change the search criteria. So it's not surprising that companies are willing to spend a fortune on maximising their exposure via sponsored links.

Naturally, this has helped Google to become one of the few profitable companies from the dotcom era. Of course keyword advertising is separate from the main search results, but for how long can this continue, and will search engines slowly fold to commercial pressures?

The stakes are high, and both Yahoo and now Microsoft (somewhat ironically) are looking to break the monopoly and diversify the market. However, smaller companies will only be able to take advantage of this form of advertising as competition forces pricing to fall.

How long keyword advertising will continue is anyone's guess, but there are few commercial sites that don't use it. Will it one day prove necessary to pay for searches that are in no way influenced by external companies?

Meanwhile Google is trialling a somewhat controversial form of email to include advertising based on keywords found within sent emails.

This throws up all sorts of ugly privacy issues, but could this be a way of maintaining revenue and satisfying investors, while keeping search results clear of commercial interests?

Whatever the future holds, search engines are an important part of the internet infrastructure and it may mean putting up with advertising within emails to maintain well defined search results.

Whether the search engine era makes you a millionaire or proves to be just another blip in technology history, it is clear is that whoever controls search engines - either paid for or free - has incredible influence over what we view on the internet.