THE METHUSELAH of online services, CompuServe, is now offering ad space targeting its 400,000 UK members by lifestyle or profession. [How? Debrief's editor is a member and has no recall of ever being asked the relevant questions. All CompuServe knows about this decrepit hack is his address and credit card details; neither of which reveal his shameful profession and sordid lifestyle.] CompuServe claims the majority of its members are in the 25-45 age group, with a household income over £25,000 pa, and guarantees advertisers a given level of hits.