It would be impolite to mention who the client is or specific numbers, but let's say this is a fiction based on recent experience:<p>FooCorp is a well-known software company which makes FooBar, a product virtually synonymous with bar. FooBar's rankings for [bar] suck because FooCorp has a longstanding institutional distrust of SEO which they are only recently recovering from. FooBar's yearly sales are $5 million. Successfully implementing my recommendations regarding SEO and conversion funnels would, conservatively, increase that to $6 million. The marginal $1 million is about 95% profit.<p>I worked at FooCorp for <i>two weeks</i>. Pretend the client is operating on Google scales, where $1 million is penny ante and barely rates a mention in a weekly summary email. Now pretend that the engineer works for four years. Now pretend that the engineer is provably responsible for at least one 5% improvement in a core revenue-generating Google product (<i>cough</i> only two choices here <i>cough</i>). Now pretend that improvement was highly non-obvious and Google does not believe it would be easy to replicate if they only had a team of genius PhDs and infinite money to throw at the problem. Now pretend that said employee is reasonably expected to do more good work in the future... and just said he wants to go to Facebook.<p>You tell me, is he <i>really</i> worth $3.5 million?