Hi again Michael,
From previous postings on this subject it seems as if most w/c cross-promote several services either on the back of their 'your windows have been cleaned today' cards or on seasonal flyers to existing customers.
We all have a ready made market for add-ons - this being our own customer base.
Just a few of the add-ons w/c can eaily do are :-
1. Gutter cleaning
2. Upvc cleaning
3. Sofitts/eaves etc cleaning
4. garage door cleans
5. Patio blasting (needs a Karcher or similar)
6. Grass cutting
Im sure there are many more but the big earner is gutter cleaning which is usually seasonal in Sept/Oct and March/ April although we do then all the time.
If you do a search on any of the above you will get some more info on each and details on any equipment you would need.
Hope that gives you a starting point, regards,
Sarah