Like most things; it's horses for courses and a lot depends on your expectations.
If you expect to get a shedload of sales then as stugster points out you will likely be disappointed. He also points out that if you commit to it and go regularly then it just might pay off at some time in the future.
Business owners make the same mistake getting involved in social media; their expectation of both what it is and what they can expect to get from it. Too many assume all you have to do is just be there or regard it as another advertising medium.
Neither are and need commitment in time, effort and funds to fully benefit. In the case of networking I believe there is generally a £10/£15 cost for each meeting so the annual financial input could be £1000 including meeting, travel and other incidental costs.
The same applies to social media requiring input in terms of responding to tweets, commenting on blogs, maintaining a Facebook fan page; all of which has a cost to the business.
Not being a member of BNI don't know, but is it not the case that only one type of business member is allowed in each chapter which might improve the business opportunities from members and their referrals.
And, then there is opportunity cost. What alternatives are out there that £1000 could be spent on that might generate additional leads and potential sales?
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Rob Willox
WebMedia | SEO & Conversion Optimisation
Website design Falkirk, Search Engine Optimisation (seo) Falkirk, Edinburgh & Scotland