'substantial foothold' is correct and usable in written English.
It is used to indicate a significant level of influence, control, or power in a particular area. For example, "After months of hard work, the company has gained a substantial foothold in the market."
When Ahmadinejad became president in 2005, the radicals had aligned themselves with him and for the first time gained a substantial foothold in the government.
Deutsche Telekom offered more than $50 billion in stock for VoiceStream, of Bellevue, Wash., to gain its first substantial foothold in the United States.
With it went the Iberian carrier's substantial foothold in South America.With all this on Mr Allen's shoulders, it is not surprising that he would want to seek a safe refuge before turning over the helm.
But several American businessmen involved in ventures in Iraq said that Chalabi had gained a substantial foothold in the country's financial sector, by insuring that relatives and longtime loyalists held key positions.
It also gives it a substantial foothold in the mobile hardware business.
But the move is also huge for EDS, which now gains a substantial foothold in the B2B e-commerce arena.
Equity Office's substantial footholds in West Los Angeles and Boston were among the chief reasons that Steven Roth, the chairman of Vornado Realty Trust, tried to wrest the company away from Blackstone.
That those companies had started to gain a sufficiently strong foothold in the K-12 market to attract substantial investment indicated that they were clearly providing products that sufficiently many schools and school districts, in particular, were finding useful.
The wilderness has a strong foothold here.
It has a strong foothold in one state.
The concept of immunotherapy has gained a strong foothold in the AD field [ 6].
