I use Adwords for various things at various times of the year and I think it's fantastic. It's a decent substitute if your website is not on page one for the keyword you want. Can be a rip off if you use the default settings. My biggest single piece of advice to save you a huge amount of money is to set your search results to 'exact match'. Then someone will have to type in 'window cleaner Telford' to find your ad. On 'broad match', if someone types in just 'Telford', your ad may still show, they may still click even though they have no intention of looking for a window cleaner and then you still pay for your click.
As a real life example, I type in solar-related search terms to help tweak underperformance pages. If I type in 'solar panel cleaning Telford' one company (who is on the forum) always comes up that is miles away and I know they don't cover Telford at all in their ad or on their website. My guess is that their search term is on a national basis when it needs to be local and is on a broad match so that as soon as somebody types 'solar panel cleaning......' their ad shows. Their Adwords campaign must be costing a small fortune if it is set up this way. People all over the UK may be clicking and costing him money even though he never services their area. What a waste!
Set up properly though, Adwords can make you a lot of extra money.