Learn English – The difference between during a week and during the week

The 'rule' is that you change temporal references if the facts require it.

For instance, ago designates a timespan whose end lies at ‘Speech time’ (ST), the time a speech is uttered. If the STs of the speech and the report lie within the same timeframe, there is no need to adjust the reference:

“I joined the company three years ago.”
Mr. Jones said yesterday that he joined the company three years ago.

But if the STs of the speech and the report lie within different timeframes, the reference may have to be adjusted.

“I joined the company three years ago.”
Mr. Jones said in 1993 that he had joined the company three years before. —or ‘previously’ or ‘earlier’ or something of the sort.

“I joined the company exactly three years ago, to the day.”
Mr. Jones said yesterday that he had joined the company exactly three years before, to the day.

Other terms which refer to ST Terms—tomorrow, yesterday, last year, next week—similarly require adjustment when STs get out of synch.

“We can deliver next week.”
He said this morning that they can deliver next week.
He said two weeks ago that they could deliver the next week. or ‘the following week’, OR
He said two weeks ago that they could deliver last week.

In the first clause, "eBay ..... now [spend] $20m a year analysing suspicious sales" the verbs spend is wrongly conjugated. It should be spends because eBay is a singular noun in this sense.

As you once believed, the adverb now can be used regardless of the verb being stative or dynamic. You were right.

eBay now spends $20m a year analysing suspicious sales.

This is the correct present simple form.

eBay is now spending $20m a year analysing suspicious sales.

This is the correct present continuous form.