It is good practice to use the Alt Attribute appropriately for accessibility purposes DDA compliance etc. The Alt attribute doesn't work in all browsers (eg Firefox) but the Title does so therefore it is good design design practice to use both.
Also as you point out Martin, they both help in getting featured in Google (and Co) Image search results. These visitors can be voluminious and usualyy only a very small percentage will be of any commarecial use. However if you work at Image search optimisation, the numbers can be enough to make that small percentage worthwhile. For example, I have achieved several thousand Image Search visitors per day for one client and this translates to over a thousand pounds in daily sales. Well worth the effort and extra bandwidth.
Remember though that to be really effective, the Alt and Title should be descriptive or relevent to the Image itself and in most cases, incorporate a few words relevent to the context of nearby on page text.
|