Analysts and shareholders, uneasy about the multi-billion-dollar project, hoped Paris would be a turning point.
The 100-150 seat C-Series is two years late and over-budget.
Mr Cromer played down the show's importance for C-Series announcements, saying it provided brand "momentum".
Bombardier, which has a big operation in Belfast, has seen rivals unveil a series of deals in the show's first two days.
Mr Cromer was appointed as part of a wider management shake-up at the Canadian company, and the planemaker has a big presence at Paris show.
Cost overruns pushed Bombardier into a loss last year, its first in almost a decade.
The company has 243 firm orders for the C-Series - the biggest from Lufthansa's Swiss International - and wants to have 300 by the time it enters service in the middle of next year.
"I think we feel pretty good about being able to achieve that, and potentially beating that target," Mr Cromer said. "The momentum is very tangible right now, and our job is to turn that momentum into sales."
He said: "The focus on air shows (for orders) is in some ways unnecessary. Sales is a 365-day job. We will announce deals at the appropriate time."
But a lack of order news, even small ones, in the last two days - traditionally when planemakers tout their biggest deals - will concern analysts.
In April, Rolland Vincent, a former Bombardier director, told Canada's Financial Post that without any "blockbuster" orders at Paris, the show "will be a really dark week for them".
Analysts have urged Bombardier to be more aggressive on price and offer bigger discounts in order to book more orders quickly.
But this strategy could further strain relations with some big shareholders, already concerned about mounting development costs, which have reached about $5.5bn - more than $1bn above initial forecasts.
Mr Cromer does not seem in any hurry to cut costs for a bigger market share, however.
"Everyone wants to get into the price discussion and say that if you don't cut prices you won't get orders. The fact of the matter is, this is an all-new aircraft that fits into many different airline business plans. Price is just one of the aspects during negotiations," he said.

Adur District Council said it was looking into the possibility of a memorial walk along the River Adur.
People are being invited to submit their thoughts and suggestions to the shorehamremembers.org website.
A shortlist of ideas will be created in January, followed by a public consultation in March.
Eleven men were killed on 22 August when a vintage Hawker Hunter plummeted into the A27 in West Sussex during the Shoreham Air Show.
In a statement, Adur District Council said: "It has been suggested that a new memorial, close to both the river and the proposed site for a new slipway, could form the start and finish of a beautiful walk between the recreation ground and Old Tollbridge.
"This idea potentially also incorporates the temporary memorial board and archway erected by the county council in a meaningful way, and could create a multitude of spaces and perspectives for reflection along the walk's length."
It continues: "While other ideas are being invited this particular one appears to be currently gathering support throughout the community."
In the days after the crash, thousands of flowers, cards, pictures and messages of condolence were left on the Old Shoreham Toll Bridge, which became known as the "Bridge of Flowers".
A memorial service was held at Lancing College's gothic chapel on 22 November, three months after the disaster.
During the service, the Bishop of Chichester, The Right Reverend Dr Martin Warner, praised the "human courage, generosity and compassion" of the emergency services and said this was a time when "grief must blend with love" in a celebration of those who died.

Det Supt Tanya Jones said a member of the public discovered the body in the Basingstoke Canal at Woodham Lock in West Byfleet on Saturday.
Detectives are treating his death as suspicious. Officers are looking into the circumstances that led to him being found in the water.
Police believe they know who the man is and have informed his family, but have not yet released his name.
Officers want to speak to anyone who was on the towpath, lock bridge or nearby footpaths between Friday night and Saturday morning and who might have heard or seen anything suspicious.
New Bombardier president Fred Cromer says the planemaker is still set to meet sales targets for its key C-Series aircraft, despite so far failing to announce orders at the Paris Air Show.
[NEXT_CONCEPT]
A permanent memorial is to be created as a "fitting, lasting tribute" to the 11 men who were killed in the Shoreham air disaster in August.
[NEXT_CONCEPT]
A man's body has been pulled from a canal in Surrey.